Phase change material packaging structure and battery module

Abstract

The utility model discloses a phase-change material packaging structure, which is characterized in that a core material is used as a supporting carrier of a phase-change material, and a large amount of energy generated during thermal runaway of a battery is absorbed by the phase-change material in a phase-change process, so that heat spreading is avoided; the core material absorbing the phase change material is wrapped in the packaging film, and the heat sealing area on the periphery of the packaging film is bent after being subjected to hot pressing, so that the space occupied by the heat sealing area is reduced, the volume utilization rate of the packaging structure is improved, and the volume and the phase change enthalpy value of the phase change material can be increased in the space with the same size; and secondly, the packaging structure of the phase change material is simple, and compared with a packaging plate, no complex plate or grid structure exists, so that the cost and the weight of the part are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a phase change material packaging structure and a battery module. Background Art

[0002] With the rapid development of electric vehicles, the safety of battery systems has received more attention. When a vehicle experiences thermal runaway, it is usually caused by a single battery cell. After the battery cell goes into thermal runaway, a large amount of heat is released in a short period of time, igniting other batteries to go into thermal runaway, and eventually the heat spreads to the entire battery pack. Phase change materials have excellent heat absorption capacity and can effectively delay or inhibit the spread of heat during thermal runaway.

[0003] Existing phase change material packaging structures are mostly packaging plates and packaging boxes, such as the patent with publication number CN205919726U, in which the phase change material packaging plate disclosed includes an insulation back plate, a sealing plate, a grille plate, a heat exchange plate, etc. The grille plate is vertically staggered and fixed with several vertical and horizontal strips to form a grid. The structure is complex, the cost is high, the volume utilization rate is low, and the sealing performance is poor, making it difficult to promote phase change materials on a large scale in the battery industry that pursues higher space utilization. If a packaging film is used to wrap the phase change material and the packaging film is heat-pressed and sealed on all sides, the seal width occupies the volume of the phase change material packaging structure, and the overall volume utilization rate of the phase change material is low. Utility Model Content

[0004] The main purpose of the present application is to provide a phase change material packaging structure, aiming to solve the problem of low volume utilization of the existing phase change material packaging structure.

[0005] In order to achieve the above-mentioned objectives, the first aspect of the utility model proposes a phase change material packaging structure, including a packaging film, a core material, and a phase change material, wherein the phase change material is provided on the core material, and the core material and the phase change material are wrapped by the packaging film. A heat sealing area for hot pressure sealing is provided around the packaging film, and at least a portion of the heat sealing area is bent.

[0006] Furthermore, the heat-sealing area includes a free end, a connecting end and an extension section, the extension section is located between the free end and the connecting end, the free end is an end away from the core material, the connecting end is an end close to the core material, and the extension section is folded 180°.

[0007] Furthermore, the connecting end of the heat-sealed area is bent toward the thickness direction of the core material.

[0008] Furthermore, the seal width of the heat-sealed area is not less than 5 mm.

[0009] Furthermore, the outer side of the heat-sealed area is wrapped with insulating material.

[0010] Furthermore, the packaging film is one or more of aluminum-plastic film, nylon film, polyimide film, polypropylene film, polyethylene film, and polyvinyl chloride film.

[0011] Furthermore, the packaging film has a thickness of 0.05 mm to 0.25 mm.

[0012] Furthermore, the core material is a fiber material, the porosity of the fiber material is 80% to 90%, and the thickness is 1 mm to 5 mm.

[0013] Furthermore, the phase change material is one or more of flame retardant gel, antifreeze gel, and thermal conductive gel.

[0014] Another aspect of the present invention provides a battery module, comprising a plurality of battery cells and at least one phase change material packaging structure as described in any of the above embodiments, wherein the phase change material packaging structure is placed between two adjacent battery cells.

[0015] Beneficial effects:

[0016] The utility model discloses a phase change material packaging structure, in which a core material serves as a supporting carrier of the phase change material, and utilizes the phase change process of the phase change material to absorb a large amount of energy generated during thermal runaway of the battery to avoid heat spread; the core material that has absorbed the phase change material is wrapped by a packaging film, and the heat-sealed area around the packaging film is subjected to hot pressing and then bent, thereby reducing the space occupied by the heat-sealed area and improving the volume utilization rate of the packaging structure, which is beneficial to increasing the volume and phase change enthalpy value of the phase change material in a space of the same size; secondly, the packaging structure of the phase change material is simple, and compared with the packaging plate, there is no complicated plate and grid structure, which is beneficial to reducing the cost and weight of the components. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of an existing phase change material packaging structure;

[0018] Figure 2 This is a schematic structural diagram of a phase change material packaging structure in one embodiment of the utility model;

[0019] Figure 3 yes Figure 2 A schematic diagram of the section in the middle;

[0020] Figure 4 yes Figure 3 The local enlarged schematic diagram of point I in the middle;

[0021] Figure 5 It is a structural schematic diagram of another phase change material packaging structure in one embodiment of the utility model;

[0022] Figure 6 yes Figure 5 Schematic diagram of the section at B;

[0023] Figure 7 yes Figure 6 A partial enlarged schematic diagram of point II in the middle;

[0024] in:

[0025] 1. Packaging film; 11. Heat-sealing area; 111. Free end; 112. Extension section; 113. Connecting end; 2. Core material; 3. Phase change material; 4. Insulating material.

[0026] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0027] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0029] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0030] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0031] Reference Figure 2-7 An embodiment of the utility model provides a phase change material packaging structure, including a packaging film 1, a core material 2, and a phase change material 3. The core material 2 is provided with the phase change material 3, and the core material 2 and the phase change material 3 are wrapped in the packaging film 1. The periphery of the packaging film 1 is provided with a heat sealing area 11 for hot pressure sealing, and at least a portion of the heat sealing area 11 is bent.

[0032] In the above embodiment, the core material 2 serves as the supporting skeleton and carrier of the phase change material 3, and utilizes the phase change process of the phase change material 3 to absorb a large amount of energy generated when the battery is thermally runaway, thereby avoiding heat spread and improving the safety performance of the battery; the core material 2 that has absorbed the phase change material 3 is wrapped by the packaging film 1, and the heat-sealed area 11 around the packaging film 1 is subjected to hot pressing and then bent, thereby reducing the space occupied by the heat-sealed area 11 and improving the volume utilization rate of the packaging structure. Figure 1 The prior art is beneficial to increase the volume of the phase change material 3 and the amount of heat that can be absorbed in a space of the same size; secondly, the packaging structure of the phase change material 3 is simple, and there is no complicated plate and grid structure compared to the packaging board, which is beneficial to reducing the cost and weight of the components.

[0033] In the above embodiment, the phase change material 3 is adsorbed on the core material 2 and is encapsulated as a whole in the cavity formed by the packaging film 1. A heat sealing area 11 is provided around the packaging film 1 to fix the position of the phase change material 3 and the core material 2 inside it unchanged and achieve overall sealing to prevent the phase change material 3 from moving or dislocating during use; the heat sealing area 11 is subjected to a bending treatment, and any area of ​​the heat sealing area 11 is bent to shorten the distance from the edge of the heat sealing area 11 to the core material 2, and reduce the space occupied by the heat sealing area 11; the specific bending structure refers to the following embodiment, and can be bent by manual bending or roller rolling. The heat sealing area 11 uses a vacuum high-temperature hot pressing packaging process, and the sealing process is simple, high in strength, low in cost, and has better sealing than the adhesive process. When the hot pressing seal width is not less than 5mm, the strength can reach 100N / 15mm, and the pressure resistance can reach 2MPa.

[0034] In the above embodiment, the core material 2 can be a square or circular mesh structure, the phase change material 3 is adsorbed in the mesh structure of the core material 2, the phase change material 3 is a liquid substance or gel with flame retardant powder, after heating, the liquid component in the liquid substance or gel absorbs the heat of the battery and vaporizes to become gas molecules, and the remaining flame retardant powder provides a flame retardant effect, prevents heat spread, and improves the safety of the phase change material 3; at least part of the heat-sealed area 11 is bent, including only part of the heat-sealed area 11 is bent and all the heat-sealed areas 11 are bent, for example Figure 2 The core material 2 is a square structure, and only the upper and lower heat-sealing areas 11 of the core material 2 are bent, while the left and right heat-sealing areas 11 are not bent. In another embodiment, in addition to the upper and lower heat-sealing areas 11 being bent, the left and right heat-sealing areas 11 of the core material 2 can also be bent to further increase the volume of the core material 2.

[0035] In one embodiment, the heat-sealing area 11 includes a free end 111, a connecting end 113 and an extension section 112, wherein the extension section 112 is located between the free end 111 and the connecting end 113, the free end 111 is an end away from the core material 2, the connecting end 113 is an end close to the core material 2, and the extension section 112 is folded 180°. Figure 2-4 The extension section 112 is folded 180 degrees to fit together, and the free end 111 approaches the connecting end 113. The two parts of the folded extension section 112 fit together. The width of the heat-sealed area 11 is halved due to folding from the middle. The free end 111 and the connecting end 113 fit together at the shortest distance, and the extension section 112 and the core material 2 remain parallel. The extension section 112 can also be folded from other areas. The two parts of the folded extension section 112 fit together. The free end 111 and the connecting end 113 are spaced apart. In terms of spacing, the phase change material packaging structure is shortened in the width direction. Since the packaging film 1 is made of flexible material, the thickness of the heat-sealing area 11 increases after bending. However, when used, the heat-sealing area 11 is squeezed by the battery cells on both sides and may produce a certain deformation to adapt to the change, and will not occupy the lateral space. It can be understood that the number of times the heat-sealing area 11 can be bent is related to the distance from the core material 2 to the edge of the heat-sealing area 11. The farther the core material 2 is from the edge of the heat-sealing area 11, the more times the heat-sealing area 11 can be bent.

[0036] Reference Figure 5-7 In the above embodiment, the connecting end 113 of the heat-sealing area 11 is bent toward the thickness direction of the core material 2. After the extension section 112 of the heat-sealing area 11 is folded 180 degrees once, the portion of the heat-sealing area 11 close to the core material 2, i.e., the connecting end 113, is bent again from the root of the heat-sealing area 11. Figure 7, the thickness direction of the core material 2 is horizontal, and the heat-sealing area 11 after bending once is bent toward the horizontal direction again. The angle between the heat-sealing area 11 originally parallel to the core material 2 and the core material is less than 180°, and the height of the phase change material packaging structure in the vertical direction is further shortened, further reducing the volume of the heat-sealing area 11 in the entire phase change material packaging structure; the angle of the second bending is preferably 90°, that is, the heat-sealing area 11 after the second bending is perpendicular to the core material 2, and the overall center of gravity of the heat-sealing area 11 is close to the core material 2. The width of the entire heat-sealing area 11 is saved, and the heat-sealing area 11 is parallel to the thickness direction of the core material 2, that is, the heat-sealing area 11 is perpendicular to the core material 2, and the heat-sealing area 11 is as a whole The closest distance to the core material 2 saves space in the height direction of the entire heat-sealing area 11, and further improves the volume utilization rate of the phase change material 3.

[0037] In one embodiment, the outer side of the heat-sealed area 11 is wrapped with an insulating material 4. The packaging film 1 has insulating properties. Since the insulating properties of the hot pressing area may be affected after the hot pressing, the insulating material 4 is wrapped outside the heat-sealed area 11 to enhance the insulation of the heat-sealed area, regardless of whether it is bent or not, and the insulating material 4 is provided in the area extending from the heat-sealed area 11 to the area wrapped with the core material 2. The insulating material 4 is preferably an insulating film, and additional insulating protection is provided by sticking the insulating film.

[0038] In one embodiment, the packaging film 1 is one or more of aluminum-plastic film, nylon film, polyimide film, polypropylene film, polyethylene film, and polyvinyl chloride film. The packaging films 1 made of these materials have good flexibility, can adapt to more complex packaging structures, and effectively prevent the external environment from affecting the packaging materials.

[0039] In the above embodiment, the thickness of the packaging film 1 is 0.05 mm to 0.25 mm. The thickness of the packaging film 1 can be any value between 0.05 mm and 0.25 mm, for example, including but not limited to 0.05 mm, 0.10 mm, 0.15 mm, 0.20 mm, and 0.25 mm.

[0040] In one embodiment, the core material 2 is a fiber material, and the porosity of the fiber material is 80% to 90%, and the thickness is 1mm to 5mm. The porosity of the fiber material can be any value between 80% and 90%, for example, including but not limited to 80%, 82%, 85%, 88%, and 90%. The finer the diameter of the fiber material, the greater the porosity, the smaller the thermal conductivity of the fiber material, and the better the thermal insulation effect, but at the same time, the weaker the adsorption capacity of the fiber material to the phase change material 3. The fiber porosity of 80% to 90% is sufficient to adsorb the phase change material 3, and can also achieve a good thermal insulation effect. The thickness of the fiber material can be any value between 1mm and 5mm, for example, including but not limited to 1mm, 2mm, 3mm, 4mm, and 5mm. The thickness and porosity of the fiber material are within the above range, and the inhibition effect on heat spread is better.

[0041] In one embodiment, the phase change material 3 is one or more of flame retardant gel, antifreeze gel, and thermal conductive gel. At room temperature, the phase change material 3 is a gel material with a thermal runaway inhibitor added, which is conducive to adsorption on the core material 2. In addition to gel, it can also be a solvent containing a flame retardant, an antifreeze agent, or a thermal conductive agent.

[0042] Another aspect of the present invention provides a battery module, comprising a plurality of battery cells and at least one phase change material packaging structure as described in any of the above embodiments, wherein the phase change material packaging structure is placed between two adjacent battery cells.

[0043] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A phase change material packaging structure, characterized in that: It includes a packaging film, a core material, and a phase change material. The core material is provided with the phase change material. The core material and the phase change material are wrapped in the packaging film. A heat sealing area for heat pressure sealing is provided around the packaging film, and at least part of the heat sealing area is bent.

2. The phase change material packaging structure according to claim 1, characterized in that: The heat-sealing area includes a free end, a connecting end and an extension section, wherein the extension section is located between the free end and the connecting end, the free end is an end away from the core material, the connecting end is an end close to the core material, and the extension section is folded 180°.

3. The phase change material packaging structure according to claim 2, characterized in that: The connecting end of the heat-sealed area is bent toward the thickness direction of the core material.

4. The phase change material packaging structure according to claim 1, characterized in that: The sealing width of the heat-sealing area is not less than 5 mm.

5. The phase change material packaging structure according to claim 1, characterized in that: The outer side of the heat-sealed area is wrapped with insulating material.

6. The phase change material packaging structure according to claim 1, characterized in that: The packaging film is one or more of an aluminum-plastic film, a nylon film, a polyimide film, a polypropylene film, a polyethylene film, and a polyvinyl chloride film.

7. The phase change material packaging structure according to claim 5, characterized in that: The packaging film has a thickness of 0.05 mm to 0.25 mm.

8. The phase change material packaging structure according to claim 1, characterized in that: The core material is a fiber material, the porosity of the fiber material is 80% to 90%, and the thickness is 1 mm to 5 mm.

9. The phase change material packaging structure according to claim 1, characterized in that: The phase change material is one of flame retardant gel, antifreeze gel and thermal conductive gel.

10. A battery module, characterized in that: The invention comprises a plurality of battery cells and at least one phase change material packaging structure according to any one of claims 1 to 9, wherein the phase change material packaging structure is arranged between two adjacent battery cells.

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