Composite protection piece, battery cell, battery module, battery pack and power utilization system

Abstract

The utility model belongs to the technical field of batteries, and discloses a composite protection piece, a battery cell, a battery module, a battery pack and a power utilization system. The composite protection piece comprises a first heat insulation layer, a heat dissipation layer, a second heat insulation layer, a first blocking layer and a second blocking layer, wherein the first heat insulation layer, the heat dissipation layer and the second heat insulation layer are sequentially stacked, the first blocking layer partially or completely isolates the contact face of the first heat insulation layer and the heat dissipation layer, and the second blocking layer partially or completely isolates the contact face of the second heat insulation layer and the heat dissipation layer. The heat dissipation layer and the heat insulation layer (namely, the heat dissipation layer and the first heat insulation layer and the heat dissipation layer and the second heat insulation layer) are separated, and heat dissipation materials in the heat dissipation layer are prevented from being embedded into the heat insulation materials in the heat insulation layer, so that the heat insulation performance of the heat insulation materials is reduced. The method is used for relieving the situation that thermal runaway of adjacent batteries is triggered by thermal waves due to transverse transfer of a large amount of heat generated by thermal runaway of single batteries in a battery module or a battery pack, and the thermal runaway can be caused by mechanical abuse, thermal abuse or electricity abuse and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field, specifically, the utility model relates to composite protection piece, electric core, battery module, battery pack and power system. BACKGROUND

[0002] The electric core can trigger heat runaway in the process of being heated, overcharged, overdischarged and mechanically collided, and once triggering heat runaway, the electric core with high energy inside can cause combustion, explosion and other phenomena, which seriously endanger life and property safety. In the battery module, if there is no good safety measure, the temperature of the heat runaway battery is so high that the heat generated thereby is enough to trigger heat runaway chain reaction in the form of heat abuse of the adjacent battery. SUMMARY

[0003] The utility model aims at at least in a certain extent solve one of the technical problems of heat runaway spreading in the battery module. For this purpose, the utility model aims at providing a composite protection piece, an electric core, a battery module, a battery pack and a power system. The composite protection piece provided by the utility model is beneficial to alleviate or inhibit the spread of heat runaway in the battery module, and improve the safety performance of the electric core, the battery module, the battery pack and the power system.

[0004] In the first aspect of the utility model, the utility model provides a composite protection piece. According to the embodiment of the utility model, the composite protection piece comprises: a first heat insulation layer, a heat dissipation layer and a second heat insulation layer which are sequentially stacked, a first barrier layer for isolating part or all of the contact surface of the first heat insulation layer and the heat dissipation layer, and a second barrier layer for isolating part or all of the contact surface of the second heat insulation layer and the heat dissipation layer. The heat dissipation layer is separated from the heat insulation layer (i.e. the heat dissipation layer and the first heat insulation layer, the heat dissipation layer and the second heat insulation layer), so as to prevent the heat dissipation material in the heat dissipation layer from being embedded into the heat insulation material in the heat insulation layer, thereby reducing the heat insulation performance of the heat insulation material. The composite protection piece is used to alleviate the heat runaway of the single battery of the battery module or the battery in the battery pack, so as to prevent the adjacent battery from triggering heat runaway due to heat wave. The heat runaway can be caused by mechanical abuse, heat abuse or electric abuse.

[0005] In addition, the composite protection piece according to the above embodiment of the utility model can also have the following additional technical features:

[0006] In some embodiments of the utility model, the composite protection piece satisfies at least one of the following (1) to (5):

[0007] (1) the thickness of the first barrier layer is 0.01mm to 0.1mm;

[0008] (2) the thickness of the second barrier layer is 0.01mm to 0.1mm;

[0009] (3) the material of the first barrier layer comprises one or more of polyethylene terephthalate film, aluminum plastic film, nylon film, polyimide film, polypropylene film, polyethylene film or polyvinyl chloride film;

[0010] (4) the material of the second barrier layer comprises one or more of polyethylene terephthalate film, aluminum plastic film, nylon film, polyimide film, polypropylene film, polyethylene film or polyvinyl chloride film.

[0011] In some embodiments of the utility model, the first heat insulation layer and the second heat insulation layer are symmetrically distributed with the heat dissipation layer as a reference; and / or, the first barrier layer and the second barrier layer are symmetrically distributed with the heat dissipation layer as a reference.

[0012] In some embodiments of the utility model, the thickness ratio of the first heat insulation layer, the first barrier layer and the heat dissipation layer is (30-200):(0.15-10):(20-200), and / or, the thickness ratio of the second heat insulation layer, the second barrier layer and the heat dissipation layer is (30-200):(0.15-10):(20-200).

[0013] In some embodiments of the utility model, the composite protective piece meets at least one of the following (1)-(4):

[0014] (1) the thickness of the first heat insulation layer is 0.3mm-2.0mm;

[0015] (2) the thickness of the second heat insulation layer is 0.3mm-2.0mm;

[0016] (3) the thickness of the heat dissipation layer is 0.2mm-2.0mm;

[0017] (4) the overall thickness of the first heat insulation layer, the first barrier layer, the heat dissipation layer, the second barrier layer and the second heat insulation layer is 0.5mm-4.1mm.

[0018] In some embodiments of the utility model, the composite protective piece meets at least one of the following (1)-(3):

[0019] (1) the thermal conductivity of the first heat insulation layer is 0.001W / m 2 ·K-0.7W / m 2 ·K;

[0020] (2) the thermal conductivity of the second heat insulation layer is 0.001W / m 2 ·K-0.7W / m 2 ·K;

[0021] (3) the thermal conductivity of the heat dissipation layer is more than ten times of the thermal conductivity of the first heat insulation layer or the second heat insulation layer.

[0022] In some embodiments of the utility model, the material of the first thermal insulation layer and / or the second thermal insulation layer comprises at least one of aerogel thermal insulation cotton material, mica sheet, vacuum insulation board, asbestos, glass wool, expanded perlite, slag wool, foamed ceramic and felt pad.

[0023] In some embodiments of the utility model, the material of the heat dissipation layer comprises phase change material and / or chemical heat storage material.

[0024] The composite protection piece further comprises a packaging layer, and the packaging layer is wrapped on the whole structure of the first thermal insulation layer, the first barrier layer, the heat dissipation layer, the second barrier layer and the second thermal insulation layer.

[0025] In a second aspect of the utility model, the utility model provides an electric core, and at least one side of the electric core is provided with the composite protection piece.

[0026] In a third aspect of the utility model, the utility model provides a battery module, comprising at least two electric cores, and the composite protection piece is arranged between the at least two electric cores.

[0027] In a fourth aspect of the utility model, the utility model provides a battery pack, and the battery pack has the battery module of the above embodiments.

[0028] In a fifth aspect of the utility model, the utility model provides a power utilization system, comprising a power utilization equipment and the battery pack of the above embodiments.

[0029] The additional aspects and advantages of the utility model will be partially given in the following description, partially will become obvious from the following description, or be understood through the practice of the utility model. BRIEF DESCRIPTION OF DRAWINGS

[0030] The above and / or additional aspects and advantages of the utility model will become apparent and more readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0031] Figure 1 It is the structure schematic view of composite protection piece according to the utility model embodiments;

[0032] Figure 2 It is the structure schematic view of composite protection piece according to the utility model embodiments, and the heat dissipation layer is wrapped;

[0033] Figure 3Is a structure schematic view of the composite protection piece according to the embodiment of the utility model, and the first heat insulation layer and the second heat insulation layer are covered;

[0034] Figure 4 Is a structure schematic view of the composite protection piece according to the embodiment of the utility model, and the first heat insulation layer, the second heat insulation layer and the heat dissipation layer are covered;

[0035] Figure 5 Is a performance test assembly structure diagram according to the utility model.

[0036] Fig. 1-1st heat insulation layer, 2-heat dissipation layer, 3-2nd heat insulation layer, 4-1st barrier layer, 5-2nd barrier layer, 6-packaging layer, 7-composite protection piece, 8-1st battery, 9-2nd battery, 10-3rd battery, 11-4th battery, 12-5th battery. DETAILED DESCRIPTION

[0037] The embodiments of the utility model are described in detail below, and the examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the utility model, and cannot be understood as a limitation of the utility model.

[0038] In the description of the utility model, it is understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and cannot be understood as indicating or implying that the indicated elements must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the utility model.

[0039] In addition, the terms "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the utility model, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0040] In the utility model, unless another definite provision and limitation, "install", "link", "connect", "fix" and so on term should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or be integrated;Can be mechanical connection, also can be electrical connection;Can be direct connection, also can through intermediate medium indirectly connect, can be two element inside's intercommunication or two element's mutual action relationship, unless another definite limitation.For ordinary skilled person in the art, can understand the concrete meaning of above-mentioned term in the utility model according to specific circumstances.

[0041] In the utility model, unless another definite provision and limitation, first feature is "on" or "under" second feature can be that first and second features directly contact, or first and second features indirectly contact through intermediate medium.Moreover, first feature "over", "above" and "on" second feature can be that first feature is directly above or obliquely above second feature, or just indicates that the horizontal height of first feature is higher than that of second feature.First feature "under", "below" and "under" second feature can be that first feature is directly below or obliquely below second feature, or just indicates that the horizontal height of first feature is less than that of second feature.

[0042] In the first aspect of the utility model, the utility model provides a composite protection piece, referring to the accompanying Figure 1 The composite protection piece comprises: a first heat insulation layer 1, a heat dissipation layer 2 and a second heat insulation layer 3 which are sequentially stacked, a first barrier layer 4 for isolating part or all of the contact surface of the first heat insulation layer 1 and the heat dissipation layer 2, and a second barrier layer 5 for isolating part or all of the contact surface of the second heat insulation layer 3 and the heat dissipation layer 2.

[0043] The heat dissipation layer 2 is separated from the heat insulation layer (i.e. the heat dissipation layer 2 is separated from the first heat insulation layer 1 and the second heat insulation layer 3), so that the heat dissipation material in the heat dissipation layer 2 is prevented from being embedded into the heat insulation material in the heat insulation layer, thereby reducing the heat insulation performance of the heat insulation material. The composite protection piece can reduce the heat generated by the thermal runaway of the battery cells in the battery module or the battery pack, thereby reducing the heat transfer between the adjacent battery cells and preventing the thermal runaway of the adjacent battery cells.

[0044] The principle of the battery cell capable of achieving the beneficial effects of the utility model will be described in detail as follows:

[0045] With the rapid development of electrochemical energy storage systems, its problems are also quickly highlighted. For example, lithium ion battery, at present, the lithium iron phosphate blade battery assembled into a module uses glass fiber aerogel thermal insulation cotton to block the heat transfer between the module cells, trying to achieve that when the single cell triggers thermal runaway, it will not trigger thermal runaway of adjacent cells due to heat spread. However, the commonly used glass fiber aerogel thermal insulation cotton cannot effectively inhibit the spread of thermal runaway in the module under limited thickness, and even the ceramic fiber aerogel or pre-oxidized fiber aerogel material with better thermal insulation performance needs very thick thermal insulation cotton to reduce the surface temperature of the thermal runaway battery below the safety temperature of the battery, which cannot meet the requirement of inhibiting the spread of battery thermal runaway with limited thermal insulation cotton thickness.

[0046] In order to inhibit the spread of battery thermal runaway, the prior art has a protective pad containing a thermal insulation layer and a heat absorption layer for lithium ion battery, which can achieve certain effect, but because there is no effective barrier between the thermal insulation layer and the heat absorption layer, the heat absorption material may enter the thermal insulation material. The thermal insulation material such as aerogel relies on its porous structure to have good thermal insulation performance, and the embedding of heat absorption material will undoubtedly reduce the thermal insulation performance of the thermal insulation material. In addition, the prior art also has a material for lithium battery thermal insulation, which is composed of an intermediate base layer, a first XPE foaming layer and a second XPE foaming layer at both ends of the base layer, and a flame retardant layer outside the XPE foaming layer. This invention focuses on flame retardation, thermal insulation and heat dissipation process, but the heat dissipation material is in close contact with the surface of the battery. It has a certain inhibitory effect in the early stage of battery thermal runaway, but once the battery thermal runaway occurs, its spread cannot be inhibited.

[0047] The protective layer provided by the embodiment of the utility model is beneficial to heat dissipation. On the one hand, the first thermal insulation layer 1 (or the second thermal insulation layer 3) in close contact with the thermal runaway battery can delay the heat transfer time of the heat generated by the thermal runaway battery to the adjacent battery; at the same time, the heat generated by the thermal runaway battery will be dissipated to the environment in the form of heat radiation and contact heat transfer, and the high-temperature gas discharged from the explosion-proof valve of the thermal runaway battery will cool the battery, and the first thermal insulation layer 1 (or the second thermal insulation layer 3) with good thermal insulation performance will inhibit the heat transfer in this short time. On the other hand, in the process of heat transfer through the second thermal insulation layer 3 (or the first thermal insulation layer 1) to the adjacent battery, the heat dissipation layer 2 will convert the heat transferred horizontally into other forms of energy for dissipation, thereby achieving effective heat dissipation and preventing heat accumulation and rapid temperature rise.

[0048] The embodiment of the utility model adopts the combination of the heat insulation layer (namely the first heat insulation layer 1 and the second heat insulation layer 3) and the heat dissipation layer 2, which is conducive to effectively reducing the heat transfer to the adjacent battery along the horizontal direction. If the heat insulation layer (namely the first heat insulation layer 1 and / or the second heat insulation layer 3) is used to suppress the thermal runaway spread of the battery, the role of the heat insulation layer is only heat preservation, and the heat generated by the thermal runaway cannot be quickly dissipated, and the effect of suppressing the thermal runaway spread of the battery is limited under a certain thickness. If only the heat dissipation layer 3 is used, and the thermal conductivity of the heat dissipation layer 2 is relatively large, a large amount of heat generated by the thermal runaway battery will be quickly transferred to the adjacent battery, which is absorbed by the adjacent battery. At this time, the heat dissipation layer 2 cannot achieve the purpose of suppressing the thermal runaway spread, and on the contrary, it will accelerate the speed of the battery thermal runaway spread. Therefore, in the embodiment of the utility model, the heat insulation layer is used to block the large amount of heat generated by the thermal runaway battery, and in a short time, there is a large temperature difference between the thermal runaway battery and the environment, and the battery can quickly dissipate heat to the environment, and the rest of the heat is transferred to the adjacent battery. In this process, the heat insulation layer cannot block part of the heat, and the heat dissipation layer 2 is used to absorb the heat transferred horizontally and convert it into other forms of energy storage or release, thereby reducing the heat absorbed by the adjacent battery, so as to achieve the purpose of reducing the thermal runaway spread or slowing down the speed of the thermal runaway spread.

[0049] In the embodiment of the utility model, the first barrier layer 4 is arranged between the first heat insulation layer 1 and the heat dissipation layer 2, and the second barrier layer 5 is arranged between the second heat insulation layer 3 and the heat dissipation layer 2, so as to prevent the first heat insulation layer 1 and the heat dissipation layer 2 from directly contacting, and prevent the second heat insulation layer 3 and the heat dissipation layer 2 from directly contacting. This is because, if the first heat insulation layer 1 and the heat dissipation layer 2 directly contact, and the second heat insulation layer 3 and the heat dissipation layer 2 directly contact, the materials in the heat dissipation layer 2 are mixed or embedded in the materials of the corresponding first heat insulation layer 1 or second heat insulation layer 3, which reduces the heat insulation performance of the first heat insulation layer 1 and / or the second heat insulation layer 3, and affects the effect of suppressing the thermal runaway spread of the overall protection member. In a specific example, a person skilled in the art can select the first barrier layer 4 to isolate part of the contact surface of the first heat insulation layer 1 and the heat dissipation layer 2, or select the first barrier layer 4 to isolate all the contact surfaces of the first heat insulation layer 1 and the heat dissipation layer 2; select the second barrier layer 5 to isolate part of the contact surface of the second heat insulation layer 3 and the heat dissipation layer 2, or select the second barrier layer 5 to isolate all the contact surfaces of the second heat insulation layer 3 and the heat dissipation layer 2.

[0050] The structure of the first barrier layer 4 for isolating the first heat insulation layer 1 and the second heat dissipation layer 2 is not particularly limited, and a person skilled in the art can select according to actual needs. The structure of the second barrier layer 5 for isolating the second heat insulation layer 3 and the second heat dissipation layer 2 is not particularly limited, and a person skilled in the art can select according to actual needs.

[0051] According to some specific embodiments of the present application, the isolation structure of the first barrier layer 4 on the contact surface between the first thermal insulation layer 1 and the heat dissipation layer 2 comprises:

[0052] (1) The first barrier layer 4 is arranged between the first thermal insulation layer 1 and the heat dissipation layer 2, as shown in FIG. 1; Figure 1

[0053] (2) The first barrier layer 4 covers the heat dissipation layer 2, as shown in FIG. 2; Figure 2

[0054] (3) The first barrier layer 4 covers the first thermal insulation layer 1, as shown in FIG. 3; Figure 3

[0055] (4) The first barrier layer 4 independently covers the first thermal insulation layer 1 and the heat dissipation layer 2, as shown in FIG. 4. Figure 4

[0056] According to some specific embodiments of the present application, the isolation structure of the second barrier layer 5 on the contact surface between the second thermal insulation layer 3 and the heat dissipation layer 2 comprises:

[0057] (1) The second barrier layer 5 is arranged between the second thermal insulation layer 3 and the heat dissipation layer 2, as shown in FIG. 5; Figure 1

[0058] (2) The second barrier layer 5 covers the heat dissipation layer 2, as shown in FIG. 6; Figure 2

[0059] (3) The second barrier layer 5 covers the second thermal insulation layer 3, as shown in FIG. 7; Figure 3

[0060] (4) The second barrier layer 5 independently covers the second thermal insulation layer 3 and the heat dissipation layer 2, as shown in FIG. 8. Figure 4

[0061] Further, for the covering of the heat dissipation layer 2, the first barrier layer 4 can be used for covering, the second barrier layer 5 can be used for covering, or the first barrier layer 4 and the second barrier layer 5 can be arranged on the two sides of the heat dissipation layer 2 for combined covering.

[0062] In the present application, the thickness of the first barrier layer 4, the thickness of the second barrier layer 5, the material of the first barrier layer 4, and the material of the second barrier layer 5 are not particularly limited, and can be selected according to actual needs by those skilled in the art.

[0063] ​​​​​​​​(1) the thickness of the first barrier layer 4 is 0.01mm-0.1mm; in specific examples, the thickness of the first barrier layer 4 is 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.07mm, 0.08mm, 0.09mm or 0.1mm, etc.

[0064] (2) the thickness of the second barrier layer 5 is 0.01mm-0.1mm; in specific examples, the thickness of the second barrier layer 5 is 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.07mm, 0.08mm, 0.09mm or 0.1mm, etc.

[0065] (3) the material used by the first barrier layer 4 includes one or more of polyethylene terephthalate film (PET film), aluminum plastic film, nylon film, polyimide film, polypropylene film, polyethylene film or polyvinyl chloride film;

[0066] (4) the material used by the second barrier layer 5 includes one or more of polyethylene terephthalate film (PET film), aluminum plastic film, nylon film, polyimide film, polypropylene film, polyethylene film or polyvinyl chloride film.

[0067] In the embodiments of the utility model, the thickness of the first barrier layer 4 is 0.01mm-0.1mm, the contact surface of the first heat insulation layer 1 and the heat dissipation layer 2 is effectively isolated without significantly increasing the overall thickness of the composite protective piece, and the heat insulation performance of the first heat insulation layer 1 is not affected. In the embodiments of the utility model, the thickness of the second barrier layer 5 is 0.01mm-0.1mm, the contact surface of the second heat insulation layer 3 and the heat dissipation layer 2 is effectively isolated without significantly increasing the overall thickness of the composite protective piece, and the heat insulation performance of the second heat insulation layer 3 is not affected. In the embodiments of the utility model, by selecting the type of material used by the first barrier layer 4 and / or the second barrier layer 5, the barrier effect is effectively improved.

[0068] According to some specific embodiments of the utility model, the first heat insulation layer 1 and the second heat insulation layer 3 are symmetrically distributed with the heat dissipation layer 2 as the reference; and / or, the first barrier layer 4 and the second barrier layer 5 are symmetrically distributed with the heat dissipation layer 2 as the reference.

[0069] In the embodiments of the utility model, the structures on both sides of the heat dissipation layer 2 are symmetrically distributed, which is beneficial to promote the symmetrical and uniform transmission of heat and improve the safety of the battery module and the battery pack.

[0070] In this embodiment of the present invention, the thicknesses of the first heat insulation layer 1, the first barrier layer 4, and the heat dissipation layer 2 are not particularly limited, and those skilled in the art can select them according to actual needs; the thicknesses of the second heat insulation layer 3, the second barrier layer 5, and the heat dissipation layer are not particularly limited, and those skilled in the art can select them according to actual needs. According to some specific embodiments of the present invention, the thickness ratio of the first heat insulation layer 1, the first barrier layer 4, and the heat dissipation layer 2 is (30-200):(0.15-10):(20-200), and / or, the thickness ratio of the second heat insulation layer 3, the second barrier layer 5, and the heat dissipation layer 2 is (30-200):(0.15-10):(20-200). In specific examples, the thickness ratio of the first heat insulation layer 1, the first barrier layer 4, and the heat dissipation layer 2 is 200:1:20, 150:1:20, 100:1:20, 50:1:20, 3:1:20, 200:5:20, 200:10:20, 200:5:50, 200:5:100, 200:5:150, 200:5:200, etc.; in specific examples, the thickness ratio of the second heat insulation layer 3, the second barrier layer 5, and the heat dissipation layer 2 is 200:1:20, 150:1:20, 100:1:20, 50:1:20, 3:1:20, 200:5:20, 200:10:20, 200:5:50, 200:5:100, 200:5:150, 200:5:200, etc.

[0071] In this embodiment of the invention, the thicknesses of the first heat insulation layer 1, the first barrier layer 4, and the heat dissipation layer 2 are within an appropriate ratio range, which helps to further promote the synergistic effect of heat insulation and heat dissipation and improve the effect of mitigating heat spread.

[0072] In this embodiment of the invention, the thicknesses of the second heat insulation layer 3, the second barrier layer 5, and the heat dissipation layer 2 are within an appropriate proportional range, which is conducive to further promoting the synergistic effect of heat insulation and heat dissipation, and improving the effect of mitigating heat spread.

[0073] In this utility model, the thickness of the first heat insulation layer 1, the thickness of the second heat insulation layer 3, the thickness of the heat dissipation layer 2, and the thickness of the overall structure of the covering layer are not particularly limited, and those skilled in the art can choose according to actual needs. According to some specific embodiments of this utility model, the composite protective component satisfies at least one of the following (1) to (4):

[0074] (1) The thickness of the first heat insulation layer 1 is 0.3mm to 2.0mm; in specific examples, the thickness of the first heat insulation layer 1 is 0.3mm, 0.5mm, 1.0mm, 1.5mm, 2.0mm, etc.

[0075] (2) the thickness of the second thermal insulation layer 3 is 0.3mm-2.0mm; in specific examples, the thickness of the second thermal insulation layer 3 is 0.3mm, 0.5mm, 1.0mm, 1.5mm, 2.0mm, etc.;

[0076] (3) the thickness of the heat dissipation layer 2 is 0.2mm-2.0mm; in specific examples, the thickness of the heat dissipation layer 2 is 0.2mm, 0.5mm, 1.0mm, 1.5mm, 2.0mm, etc.;

[0077] (4) the overall thickness of the first thermal insulation layer 1, the first barrier layer 4, the heat dissipation layer 2, the second barrier layer 5 and the second thermal insulation layer 3 is 0.5mm-4.1mm; in specific examples, the overall thickness is 0.5mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, etc.

[0078] In the embodiment of the utility model, the thickness of the first thermal insulation layer 1 and / or the second thermal insulation layer 3 is 0.3mm-2.0mm; under a proper thickness, it is beneficial to effectively block the horizontal heat transfer while ensuring the effective heat dissipation of the heat dissipation layer.

[0079] In the utility model, the thermal conductivity of the first thermal insulation layer 1, the thermal conductivity of the second thermal insulation layer 3 and the thermal conductivity of the heat dissipation layer 2 are not particularly limited, and the person skilled in the art can select according to actual requirements. According to some specific embodiments of the utility model, the composite protective piece meets at least one of the following (1)-(3):

[0080] (1) the thermal conductivity of the first thermal insulation layer 1 is 0.001W / m 2 ·K-0.7W / m 2 ·K; in specific examples, the thermal conductivity of the first thermal insulation layer 1 is 0.001W / m 2 ·K, 0.005W / m 2 ·K, 0.01W / m 2 ·K, 0.05W / m 2 ·K, 0.1W / m 2 ·K, 0.5W / m 2 ·K or 0.7W / m 2 ·K, etc.;

[0081] (2) the thermal conductivity of the second thermal insulation layer 3 is 0.001W / m 2 ·K-0.7W / m 2 ·K; in specific examples, the thermal conductivity of the first thermal insulation layer 1 is 0.001W / m 2 ·K, 0.005W / m 2 ·K, 0.01W / m 2 ·K, 0.05W / m 2• K, 0.1 W / m 2 • K, 0.5 W / m 2 • K or 0.7 W / m 2 • K or more;

[0082] (3) The thermal conductivity of the heat dissipation layer 2 is more than ten times that of the first or second thermal insulation layer 1 or 3; in specific examples, the thermal conductivity of the heat dissipation layer 2 is 10, 15, 20, 25, 30, 35, 40, 45, or 50 times that of the first or second thermal insulation layer 1 or 3.

[0083] Further, in the embodiments of the present application, the thermal conductivity of the first thermal insulation layer 1 and / or the second thermal insulation layer 3 is 0.001 W / m 2 • K ~ 0.7 W / m 2 • K, the first and second thermal insulation layers 1 and 3 can block a large amount of heat generated by the thermal runaway battery, delay the time required for heat transfer to adjacent batteries, and at the same time allow the thermal runaway battery to exchange heat with the external environment to cool down. However, under the limited thickness, only relying on the thermal insulation layer (the first thermal insulation layer 1 and / or the second thermal insulation layer 3), it can only play a role similar to heat preservation, therefore, in order to enhance the effect of the composite protective member in inhibiting the spread of thermal runaway, the heat passing through the thermal insulation layer (the first thermal insulation layer 1 or the second thermal insulation layer 3) is absorbed by the heat dissipation layer 2 and converted into other forms of energy for dissipation, thereby further weakening the heat transferred laterally by the thermal runaway battery. The thermal conductivity of the heat dissipation layer 2 is ten or even dozens of times that of the thermal insulation layer (the first thermal insulation layer 1 or the second thermal insulation layer 3), therefore, the heat near the battery being spread will quickly pass to the adjacent battery, and will not accumulate on the heat dissipation layer 2, and the heat dissipation material in the heat dissipation layer 2 will not reach the reaction temperature and will not play the corresponding role, which will cause the heat dissipation layer 2 to lose its effect, therefore, a thermal insulation layer (the first thermal insulation layer 1 or the second thermal insulation layer 3) is also needed on the other side of the heat dissipation layer 2 to block the rapid heat transfer of the heat dissipation layer 2 to the adjacent battery, and the heat dissipation material in the heat dissipation layer 2 has enough time to absorb heat and react to convert into other forms of energy for dissipation.

[0084] In the present application, the materials used for the first thermal insulation layer 1 and / or the second thermal insulation layer 3 are not particularly limited, and persons skilled in the art can select them according to actual needs. According to some specific embodiments of the present application, the materials used for the first thermal insulation layer 1 and / or the second thermal insulation layer 3 include at least one of aerogel insulation cotton material, mica sheet, vacuum insulation board, asbestos, glass wool, expanded perlite, slag wool, foamed ceramic, and felt pad. These materials have low thermal conductivity, which is beneficial to further improve the thermal insulation effect.

[0085] Further, the aerogel thermal insulation material includes at least one of glass fiber aerogel thermal insulation material, ceramic fiber aerogel thermal insulation material, pre-oxidized fiber aerogel thermal insulation material and nano-composite board thermal insulation material. The nano-composite board thermal insulation material refers to aerogel thermal insulation material added with light shielding agent, such as glass fiber aerogel thermal insulation material added with light shielding agent, ceramic fiber aerogel thermal insulation material added with light shielding agent, pre-oxidized fiber aerogel thermal insulation material added with light shielding agent, etc. Aerogel has low thermal conductivity through its porous microstructure, effectively reducing heat conduction, and has high specific surface area and certain reflection ability to infrared radiation, thus achieving good thermal insulation performance.

[0086] Further, the mass percentage of the fiber skeleton in the thermal insulation layer (the first thermal insulation layer 1 or the second thermal insulation layer 3) is 5% to 40%, and the fiber aspect ratio is 5:1 to 5000:1. Better thermal insulation effect can be provided.

[0087] Further, the material used by the first thermal insulation layer 1 and / or the second thermal insulation layer 3 contains infrared light shielding agent, and the mass percentage of the infrared light shielding agent is greater than 0 and less than 10%. In the high temperature section, i.e. above 400℃, heat transfer is mainly in the form of infrared radiation. In order to enhance the blocking effect of the thermal insulation layer (the first thermal insulation layer 1 or the second thermal insulation layer 3) on high temperature infrared radiation, infrared light shielding agent can also be added to the thermal insulation material to improve the thermal insulation effect.

[0088] Further, the light shielding agent includes at least one of carbon black, SiC, potassium hexatitanate whisker, TiO2, ZrO2, Al2O3 and coal ash. The infrared light radiation rate of the light shielding agent to 3μm to 8μm wavelength is between 45% and 100%.

[0089] Further, the aerogel thermal insulation material is a composite material of aerogel and other materials, wherein the aerogel material includes at least one of inorganic aerogel, organic aerogel, carbon aerogel, natural aerogel and carbide aerogel. Further, the inorganic aerogel includes at least one of monovalent oxide aerogel, metal-oxide aerogel, binary oxide aerogel and ternary oxide aerogel. Specifically, the monovalent oxide aerogel includes SiO2 aerogel, Al2O3 aerogel, TiO2 aerogel, Fe2O3 aerogel, MgO aerogel, Cr2O3 aerogel, MoO2 aerogel, ZrO2 aerogel, Nb2O5 aerogel, SnO2 aerogel or B2O3 aerogel; the metal-oxide aerogel includes at least one of Cu / Al2O3 aerogel, Pd / Al2O3 aerogel and Ni / Al2O3 aerogel; the binary oxide aerogel includes at least one of Al2O3 / SiO2 aerogel, P2O5 / SiO2 aerogel, B2O3 / SiO2 aerogel, Nb2O5 / SiO2 aerogel, Er2O3 / SiO2 aerogel, CuO / Al2O3 aerogel and NiO / Al2O3 aerogel; and the ternary oxide aerogel includes at least one of CuO / ZnO / Al2O3 aerogel, B2O3 / P2O5 / SiO2 aerogel, MgO / Al2O3 / SiO2 aerogel and B2O3 / P2O5 / SiO2 aerogel. Further, the organic aerogel includes at least one of resorcinol-formaldehyde (RF) organic aerogel, melamine formaldehyde (MF) aerogel and phenol formaldehyde (PF) aerogel. Further, the carbon aerogel includes at least one of carbonized RF (resorcinol and formaldehyde) aerogel (CRF aerogel), carbon nanotube aerogel and graphene aerogel. Further, the carbide aerogel includes SiC aerogel. Further, the natural aerogel includes all-natural wood aerogel.

[0090] Further, the felt pad includes, but is not limited to, at least one of organic and inorganic fiber felt materials such as glass fiber felt, ceramic fiber felt, pre-oxidized fiber felt, alumina fiber felt, zirconia fiber felt, high-silica fiber felt, aramid fiber felt, mullite fiber felt, basalt fiber felt, carbon fiber felt, spandex fiber felt, polyester fiber felt, nylon fiber felt, polyethylene terephthalate (PET) fiber felt, non-woven fabric, fiber paper, foam and the like, or one or more of foamed materials having an open pore structure.

[0091] The material of the heat dissipation layer is not particularly limited, and can be selected according to actual needs by those skilled in the art. According to some specific embodiments of the present application, the material of the heat dissipation layer includes a phase change material and / or a chemical heat storage material, which is beneficial to improve the heat dissipation effect. The chemical heat storage material can absorb heat through chemical decomposition at a specific temperature, and the phase change material usually absorbs heat through physical phase change. The temperature can be relatively stable during the chemical decomposition or physical phase change of the material.

[0092] Further, the temperature at which the phase change material changes phase and / or the temperature at which the chemical heat storage material reacts is 30℃-700℃.

[0093] Further, the heat dissipation layer 2 further includes a support framework, and the material (phase change material and / or chemical heat storage material) of the heat dissipation layer 2 is fixed in the support framework by an adhesive. This is because the material in the heat dissipation layer 2 is mostly powder or has weak brittleness, and a fiber material or a foaming material can be used as the support framework, and the heat dissipation layer 2 with a certain thickness can be obtained by mixing and pressing the adhesive.

[0094] Further, the adhesive includes at least one of sodium carboxymethyl cellulose, alginate, beta-cyclodextrin, guar gum, gum arabic, chitosan, starch, xanthan gum, carrageenan, polyvinylidene fluoride, polyethylene glycol, polyacrylic acid, polyvinyl alcohol, poly(3,4-ethylenedioxythiophene), polyacrylamide-co-dimethylammonium chloride, butadiene-styrene rubber, polyimide, polyetherimide, polyacrylonitrile, epoxy resin, biphenyl tetracarboxylic dianhydride, polyvinylpyrrolidone, polybutyl acrylate, polyamide, polymethacrylonitrile-methyl acrylate and polyurethane. Further, the mass ratio of the adhesive to the phase change material and / or the chemical heat storage material and the framework material is 0.2%-8%.

[0095] Further, the phase change material includes at least one of an organic phase change material, a hydrated salt phase change material, and a molten salt phase change material. Still further, the organic phase change material includes at least one of glycolic acid, p-bromophenol, azobenzene, acrylic acid, 2,4-dinitrotoluene, phenylacetic acid, allyl thiourea, D-3 camphor, benzylamine, tetramethylbenzene, acetamide, methyl p-bromobenzoate, 1-naphthol, glutaric acid, dichloro-p-xylene, methyl fumarate, hydroquinone, quinone, acetanilide, erythritol, succinic anhydride, benzoic acid, stilbenes, benzamide, phenazopyridine, p-aminotoluene, benzaldehyde phenylhydrazone, salicylic acid, benzoyl aniline, D-mannitol, hydroquinone, and p-aminobenzoic acid.The hydrated salt phase change material includes at least one of LiCIO3-3H2O, NH4CI-Na2SO4-10H2O, K2HPO4-6H2O, NaCI-Na2SO4-10H2O, KF-4H2O, K2HPO4-4H2O, FeBr3-6H2O, Mn(NO3)2-6H2O, LiBO2-8H2O, CaCI2-6H2O, CaCI2-12H2O, LiNO3-3H2O, LiNO3-2H2O, Na2SO4-10H2O, Na2CO3-10H2O, KFe(SO4)2-12H2O, CaBr2-6H2O, LiBr-2H2O, Na2HPO4-12H2O, Zn(NO3)2-6H2O, Mn(NO3)2-4H2O, FeCI3-6H2O, CaCI2-4H2O, CuSO4-7H2O, KF-2H2O, MgI2-8H2O, CaI2-6H2O, Ca(NO3)2-4H2O, Zn(NO3)2-4H2O, K3PO4-7H2O, K2HPO4-7H2O, Fe(NO3)3-9H2O, Mg(NO3)2-4H2O, Na2SiO3-5H2O, Na2SiO3-4H2O, Na2HPO4-7H2O, Na2S2O3-5H2O, K2HPO4-3H2O, MgSO4-7H2O, Ca(NO3)2-3H2O, Na(NO3)2-6H2O, Zn(NO3)2-2H2O, FeCI3-2H2O, Co(NO3)2-6H2O, Ni(NO3)2-6H2O, MnCI2-4H2O, CH3COONa-3H2O, LiC2H3O2-2H2O, MgCI2-4H2O, NaOH-H2O, Cd(NO3)2-4H2O, Cd(NO3)2-H2O, Fe(NO3)2-6H2O, NaAl(SO4)2-12H2O, NaAl(SO4)2-10H2O, FeSO4-7H2O, Na3PO4-12H2O, LiCH3COO-2H2O, Na2P2O7-10H2O, Al(NO3)2-9H2O, Ba(OH)2-8H2O, Al2(SO4)3-18H2O, Sr(OH)2-8H2O, Mg(NO3)2-6H2O, KAl(SO4)2-12H2O, (NH4)Al(SO4)-6H2O, LiCI-H2O, and MgCI2-6H2O.Further, the molten salt phase change material includes at least one of LiNO3 / KCl, LiNO3 / NaNO3, KNO3 / NaNO3, LiNO3 / NaCl, NaNO3 / KNO3, LiNO / silica, NaNO3 / CuO, NaNO3 / EP, KNO3 / silica, Li2CO3 / Na2CO3 / K2CO3, NaCl / CaCl2 / MgCl2, MgCl2 / NaCl, MgCl2 / KCl, Li2CO3 / K2CO3, LiCO3 / K2CO3, Na2CO3 / Li2CO3, Li2CO3 / K2CO3, NaCl / Na2CO3, Na2CO3 / NaCl, Na2SO4 / silica, Na2SO4 / SiC ceramic foam, or any ratio of the above composite phase change materials.

[0096] According to some embodiments of the present application, the composite protective member further comprises a packaging layer 6, which is wrapped outside the overall structure of the first thermal insulation layer 1, the first barrier layer 4, the heat dissipation layer 2, the second barrier layer 5, and the second thermal insulation layer 3.

[0097] In the embodiments of the present application, the packaging layer 6 prevents air from entering and eroding or deliquescent the materials of the first thermal insulation layer 1, the second thermal insulation layer 3, and the heat dissipation layer 2.

[0098] Further, the packaging layer 6 is wrapped outside the overall structure of the first thermal insulation layer 1, the first barrier layer 4, the heat dissipation layer 2, the second barrier layer 5, and the second thermal insulation layer 3, and the inside of the packaging layer 6 is in a vacuum state. This better protects the components inside the packaging layer 6 and improves the service life and safety in use.

[0099] Further, the material of the packaging layer 6 includes one or more of polyethylene terephthalate film (PET film), aluminum plastic film, nylon film, polyimide film, polypropylene film, polyethylene film, or polyvinyl chloride film.

[0100] Further, the thickness of the packaging layer 6 is 0.01mm-0.1mm. In specific examples, the thickness of the packaging layer 6 is 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, or 100μm, etc.

[0101] In a second aspect of the present application, the present application provides a battery cell, at least one side of the battery cell is provided with the composite protective member described above. According to the embodiments of the present application, the battery cell has the composite protective member described above, which is beneficial to alleviate or inhibit heat spread and improve the safety performance of the battery cell. In the embodiments of the present application, the type of the battery cell is not particularly limited, which can be a lithium ion battery cell or a sodium ion battery cell.

[0102] In a third aspect of the utility model, the utility model provides a battery module, including at least two electric cores, and the composite protection piece is arranged between at least two electric cores. According to the embodiment of the utility model, the battery module has the electric core of above embodiment. Therefore, it is favorable to alleviate or inhibit the outbreak of thermal runaway in the battery module, thereby improving the safety performance of the battery module.

[0103] In a fourth aspect of the utility model, the utility model provides a battery pack, and the battery pack has the battery module. According to the embodiment of the utility model, the battery pack has the battery module of above embodiment. Therefore, it is favorable to alleviate or inhibit the outbreak of thermal runaway in the battery pack, thereby improving the safety performance of the battery pack.

[0104] In a fifth aspect of the utility model, the utility model provides a power utilization system, and the power utilization system includes power utilization equipment and the battery pack, and the battery pack supplies power for the power utilization equipment. According to the embodiment of the utility model, the power utilization system includes the power utilization equipment and the battery pack of above embodiment, and the battery pack supplies power for the power utilization equipment. Therefore, the safety performance of the battery pack in the power utilization system is further improved, and the use demand of the consumer is further met.

[0105] Further, the power utilization equipment can be but is not limited to mobile phone, tablet computer, notebook computer, electric toy, electric tool, electric car, electric automobile, ship, spacecraft and the like. The electric toy can include fixed or mobile electric toy, for example, game machine, electric automobile toy, electric ship toy and electric aircraft toy and the like, and the spacecraft can include airplane, rocket, space shuttle and spacecraft and the like.

[0106] The embodiment of the utility model is described in detail below, and it should be noted that the embodiment described below is exemplary and is used to explain the utility model, and cannot be understood as the limitation of the utility model.

[0107] Embodiment 1

[0108] The embodiment provides a composite protection piece, and the specific structure is as shown in Figure 3 The composite protection piece is composed of: the first heat insulation layer 1, the heat dissipation layer 2 and the second heat insulation layer 3 are sequentially laminated; the first barrier layer 4 fully covers the first heat insulation layer 1, and the second barrier layer 5 fully covers the second heat insulation layer 3; and the first heat insulation layer 1 and the second heat insulation layer 3 are symmetrically arranged with the heat dissipation layer 2 as the reference, and the first barrier layer 4 and the second barrier layer 5 are symmetrically arranged.

[0109] The material of the first heat insulation layer 1 and the second heat insulation layer 2 is same: glass fiber aerogel insulation cotton with thickness of 1.0mm is used, and 5% of TiO2 sunscreen is added.

[0110] The material used for the heat dissipation layer 2 is NaHCO3 powder with a thickness of 0.9 mm, without adding adhesive and reinforcing fibers.

[0111] The materials used for the first barrier layer 4 and the second barrier layer 5 are the same: PET film with a thickness of 15 μm.

[0112] The material used for the packaging layer 6 is an aluminum plastic film with a thickness of 20 μm, which is vacuum packaged.

[0113] Example 2

[0114] This embodiment provides a composite protective piece, and the specific structure is shown in Figure 1 The composite protective piece comprises: a first heat insulation layer 1, a first barrier layer 4, a heat dissipation layer 2, a second barrier layer 5, and a second heat insulation layer 3, which are sequentially stacked; the first heat insulation layer 4 fully isolates the contact surface of the first heat insulation layer 1 and the heat dissipation layer 2, and the second heat insulation layer 5 fully isolates the contact surface of the second heat insulation layer 3 and the heat dissipation layer 2; and the first heat insulation layer 1 and the second heat insulation layer 3 are symmetrically arranged with the heat dissipation layer 2 as a reference, and the first barrier layer 4 and the second barrier layer 5 are symmetrically arranged. In addition:

[0115] The materials used for the first heat insulation layer 1 and the second heat insulation layer 2 are the same: soft mica sheet with a thickness of 1.0 mm.

[0116] The material used for the heat dissipation layer 2 is a mixed material of Mg(OH)2 and Al(OH)3 with a mass ratio of 1:3 and a thickness of 0.9 mm; it also includes a fiber skeleton material, mullite fiber reinforced material, with a mass ratio of 5%; and a carboxymethyl cellulose sodium adhesive with a mass ratio of 1.5%.

[0117] The materials used for the first barrier layer 4 and the second barrier layer 5 are the same: aluminum plastic film with a thickness of 25 μm.

[0118] The material used for the packaging layer 6 is an aluminum plastic film with a thickness of 25 μm, which is vacuum packaged.

[0119] Example 3

[0120] This embodiment provides a composite protective piece, and the specific structure is shown in Figure 4 The composite protective piece comprises: a first heat insulation layer 1, a heat dissipation layer 2, and a second heat insulation layer 3, which are sequentially stacked; the first barrier layer 4 fully covers the first heat insulation layer 1 and is vacuum packaged, the first barrier layer 1 fully covers the heat dissipation layer 2 and is vacuum packaged, and the second barrier layer 5 fully covers the second heat insulation layer 3 and is vacuum packaged; the first heat insulation layer 1 and the second heat insulation layer 3 are symmetrically arranged with the heat dissipation layer 2 as a reference, and the first barrier layer 4 and the second barrier layer 5 are symmetrically arranged. In addition:

[0121] The material used for the first thermal insulation layer 1 and the second thermal insulation layer 2 is the same: stone wool with a thickness of 1.0 mm.

[0122] The material used for the heat dissipation layer 2 is: LiNO3·3H2O phase change material with a thickness of 0.88 mm, mixed with 1% carboxymethyl cellulose sodium binder by mass fraction.

[0123] The material used for the first barrier layer 4 and the second barrier layer 5 is the same: PET film with a thickness of 20 μm.

[0124] Example 4

[0125] This embodiment provides a composite protective piece, and the specific structure is as shown in Figure 3 The composition of the composite protective piece is:

[0126] The first thermal insulation layer 1, the heat dissipation layer 2, and the second thermal insulation layer 3 are sequentially stacked; the first barrier layer 4 fully covers the first thermal insulation layer 1, and the second barrier layer 5 fully covers the second thermal insulation layer 3; and the first thermal insulation layer 1 and the second thermal insulation layer 3 are symmetrically arranged with the heat dissipation layer 2 as the reference, and the first barrier layer 4 and the second barrier layer 5 are symmetrically arranged.

[0127] In addition, the material used for the first barrier layer 4 and the second barrier layer 5 is the same, which is PET film with a thickness of 0.1 mm, and the remaining materials are the same as shown in Example 1.

[0128] Example 5

[0129] This embodiment provides a composite protective piece, and the specific structure is as shown in Figure 3 The composition of the composite protective piece is:

[0130] The first thermal insulation layer 1, the heat dissipation layer 2, and the second thermal insulation layer 3 are sequentially stacked; the first barrier layer 4 fully covers the first thermal insulation layer 1, and the second barrier layer 5 fully covers the second thermal insulation layer 3; and the first thermal insulation layer 1 and the second thermal insulation layer 3 are symmetrically arranged with the heat dissipation layer 2 as the reference, and the first barrier layer 4 and the second barrier layer 5 are symmetrically arranged.

[0131] In addition, the material used for the first barrier layer 4 and the second barrier layer 5 is the same, which is PET film with a thickness of 0.05 mm, and the remaining materials are the same as shown in Example 1.

[0132] Example 6

[0133] This embodiment provides a composite protective piece, and the specific structure is as shown in Figure 3 The composition of the composite protective piece is:

[0134] The first heat insulation layer 1, the heat dissipation layer 2 and the second heat insulation layer 3 are sequentially stacked; the first barrier layer 4 fully covers the first heat insulation layer 1, and the second barrier layer 5 fully covers the second heat insulation layer 3; and the first heat insulation layer 1 and the second heat insulation layer 3 are symmetrically arranged with the heat dissipation layer 2 as a reference, and the first barrier layer 4 and the second barrier layer 5 are symmetrically arranged.

[0135] In addition, the first barrier layer 4 and the second barrier layer 5 adopt the same material, which is a PET film with a thickness of 0.01mm, and the remaining materials are the same as shown in Example 1.

[0136] Example 7

[0137] The embodiment provides a composite protective piece, and a specific structure is shown in Figure 3 The composition of the composite protective piece comprises:

[0138] The first heat insulation layer 1, the heat dissipation layer 2 and the second heat insulation layer 3 are sequentially stacked; the first barrier layer 4 fully covers the first heat insulation layer 1, and the second barrier layer 5 fully covers the second heat insulation layer 3; and the first heat insulation layer 1 and the second heat insulation layer 3 are symmetrically arranged with the heat dissipation layer 2 as a reference, and the first barrier layer 4 and the second barrier layer 5 are symmetrically arranged.

[0139] In addition:

[0140] The first heat insulation layer 1 and the second heat insulation layer 3 adopt the same material: aerogel insulation cotton material with a thickness of 2.0mm.

[0141] The heat dissipation layer 2 adopts the material: NaHCO3 material with a thickness of 0.2mm.

[0142] The first barrier layer 4 and the second barrier layer 5 adopt the same material: PET film with a thickness of 0.01mm.

[0143] The packaging layer 6 is shown in Example 1.

[0144] Example 8

[0145] The embodiment provides a composite protective piece, and a specific structure is shown in Figure 3 The composition of the composite protective piece comprises:

[0146] The first heat insulation layer 1, the heat dissipation layer 2 and the second heat insulation layer 3 are sequentially stacked; the first barrier layer 4 fully covers the first heat insulation layer 1, and the second barrier layer 5 fully covers the second heat insulation layer 3; and the first heat insulation layer 1 and the second heat insulation layer 3 are symmetrically arranged with the heat dissipation layer 2 as a reference, and the first barrier layer 4 and the second barrier layer 5 are symmetrically arranged.

[0147] In addition:

[0148] The first heat insulation layer 1 and the second heat insulation layer 3 adopt the same material: aerogel insulation cotton material with a thickness of 0.3mm.

[0149] The material used for the heat dissipation layer 2: NaHCO3 material with a thickness of 2.0 mm.

[0150] The material used for the first barrier layer 4 and the second barrier layer 5 is the same: PET film with a thickness of 0.1 mm.

[0151] The packaging layer 6 is as shown in Example 1.

[0152] Comparative Example 1

[0153] This comparative example provides a glass fiber aerogel thermal insulation cotton material with a thickness of 3 mm as a control experimental group.

[0154] Comparative Example 2

[0155] This comparative example provides a composite protective piece, which is composed of: the first thermal insulation layer 1, the heat dissipation layer 2 and the second thermal insulation layer 3 are sequentially stacked; the first thermal insulation layer and the second thermal insulation layer are symmetrically placed. In addition:

[0156] The material used for the first thermal insulation layer 1 and the second thermal insulation layer 2 is the same: glass fiber aerogel thermal insulation cotton with a thickness of 1.0 mm, wherein a mass percentage of 5% TiO2 sunscreen is added.

[0157] The material used for the heat dissipation layer 2: NaHCO3 powder with a thickness of 0.9 mm, without adding binder and reinforcing fibers.

[0158] The material used for the packaging layer 6: aluminum plastic film with a thickness of 20 μm, and vacuum packaging is performed.

[0159] Comparative Example 3

[0160] This comparative example provides a composite protective piece, which is composed of: the thermal insulation layer 1, the heat dissipation layer 2 and the barrier layer 3, wherein the barrier layer is between the thermal insulation layer 1 and the heat dissipation layer 2

[0161] The material of the thermal insulation layer 1: glass fiber aerogel thermal insulation cotton with a thickness of 1.0 mm, wherein a mass percentage of 5% TiO2 sunscreen is added.

[0162] The material used for the heat dissipation layer 2: NaHCO3 powder with a thickness of 0.9 mm, without adding binder and reinforcing fibers.

[0163] The material of the barrier layer 3: PET film with a thickness of 15 μm.

[0164] The material used for the packaging layer 6: aluminum plastic film with a thickness of 20 μm, and vacuum packaging is performed.

[0165] Performance test:

[0166] 1. Test Method: Simulating the thermal runaway propagation of a module according to the national standard (GB / T 36276-2018), five fully charged cells (cells 1-8, 2-9, 3-10, 4-11, and 5-12) were placed side by side, with protective components prepared in the example or comparative example placed in the middle and at both ends to assemble a battery cluster. Figure 5 As shown. A 1C constant current overcharge triggered thermal runaway in cell 3 (cell 10). After cell 3 (cell 10) triggered thermal runaway, charging was stopped, and the cells were observed for 1 hour to see if other cells triggered thermal runaway. Among these:

[0167] Experiment 1: Tests were conducted using the composite protective component prepared in Example 1;

[0168] Experiment 2: Tests were conducted using the composite protective component prepared in Example 2;

[0169] Experiment 3: Tests were conducted using the composite protective component prepared in Example 3;

[0170] Experiment 4: Tests were conducted using the composite protective component prepared in Example 4;

[0171] Experiment 5: Tests were conducted using the composite protective component prepared in Example 5;

[0172] Experiment 6: Tests were conducted using the composite protective component prepared in Example 6;

[0173] Experiment 7: Tests were conducted using the composite protective component prepared in Example 7;

[0174] Experiment 8: Tests were conducted using the composite protective component prepared in Example 8;

[0175] Experiment 9: Tests were conducted using the composite protective component prepared in Comparative Example 1;

[0176] Experiment 10: Tests were conducted using the composite protective component prepared in Comparative Example 2.

[0177] Experiment 11: Tests were conducted using the composite protective component prepared in Comparative Example 3.

[0178] 2. Test results: The test results are shown in Table 1.

[0179] Table 1. Test results of thermal insulation performance

[0180]

Claims

1. A composite protective component, characterized in that, include: The first heat insulation layer, the heat dissipation layer, and the second heat insulation layer are stacked sequentially. A first barrier layer that partially or completely isolates the contact surface between the first heat insulation layer and the heat dissipation layer. A second barrier layer that partially or completely isolates the contact surface between the second heat insulation layer and the heat dissipation layer.

2. The composite protective component according to claim 1, characterized in that, The composite protective component satisfies at least one of the following (1) to (2): (1) The thickness of the first barrier layer is 0.01 mm to 0.1 mm; (2) The thickness of the second barrier layer is 0.01 mm to 0.1 mm.

3. The composite protective component according to claim 1, characterized in that, The first heat insulation layer and the second heat insulation layer are symmetrically distributed with respect to the heat dissipation layer; and / or, the first barrier layer and the second barrier layer are symmetrically distributed with respect to the heat dissipation layer.

4. The composite protective component according to any one of claims 1 to 3, characterized in that, The thickness ratio of the first heat insulation layer, the first barrier layer and the heat dissipation layer is (30~200):(0.15~10):(20~200), and / or the thickness ratio of the second heat insulation layer, the second barrier layer and the heat dissipation layer is (30~200):(0.15~10):(20~200).

5. The composite protective component according to any one of claims 1 to 3, characterized in that, The composite protective component satisfies at least one of the following (1) to (4): (1) The thickness of the first heat insulation layer is 0.3 mm to 2.0 mm; (2) The thickness of the second insulation layer is 0.3 mm to 2.0 mm; (3) The thickness of the heat dissipation layer is 0.2 mm to 2.0 mm; (4) The overall thickness of the first heat insulation layer, the first barrier layer, the heat dissipation layer, the second barrier layer and the second heat insulation layer is 0.5 mm to 4.1 mm.

6. The composite protective component according to claim 1, characterized in that, The composite protective component satisfies at least one of the following (1) to (3): (1) The thermal conductivity of the first insulation layer is 0.001 W / m 2 •K~0.7 W / m 2 •K; (2) The thermal conductivity of the second insulation layer is 0.001 W / m 2 •K~0.7 W / m 2 •K; (3) The thermal conductivity of the heat dissipation layer is more than ten times that of the thermal conductivity of the first heat insulation layer or the second heat insulation layer.

7. The composite protective component according to any one of claims 1 to 3, characterized in that, It also includes a packaging layer that covers the overall structure of the first heat insulation layer, the first barrier layer, the heat dissipation layer, the second barrier layer, and the second heat insulation layer.

8. A battery cell, characterized in that... At least one side of the battery cell is provided with the composite protective element as described in any one of claims 1 to 7.

9. A battery module, characterized in that, The battery module includes at least two battery cells, and a composite protective element as described in any one of claims 1 to 7 is disposed between the at least two battery cells.

10. A battery pack, characterized in that, The battery pack has the battery module as described in claim 9.

11. An electrical system, characterized in that, The power system includes electrical equipment and the battery pack of claim 10, wherein the battery pack supplies power to the electrical equipment.

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