Power battery heat insulation piece and power battery pack
By designing a thermally conductive layer and a thermally insulating layer in the power battery heat insulation parts, combining thermally conductive fibers and flame retardant particles, the problem that the power battery heat insulation materials cannot take into account both heat insulation and heat dissipation, and the effective heat dissipation and safety protection of the battery unit is achieved.
Patent Information
- Application Number
- CN202421408929.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-18
- Publication Date
- 2025-04-08
- Estimated Expiration
- 2034-06-18
AI Technical Summary
In the prior art, the thermal insulation materials of power batteries cannot take into account both thermal insulation and heat dissipation, resulting in the battery unit being unable to effectively dissipate heat during operation, increasing the risk of thermal runaway.
A power battery heat insulation piece is designed, including a heat insulation layer and a thermal conductivity layer. The thermal conductivity layer is composed of a thermal matrix and thermal fibers. The thermal fibers form a three-dimensional web structure, and flame retardant particles can be optionally added. The thermal conductivity layer is arranged on the upper and lower surfaces of the thermal insulation layer to achieve effective heat dissipation and heat insulation.
Through the design of the thermal conductivity layer, the battery unit can achieve good heat dissipation effect during normal operation and avoid heat accumulation; when the heat is out of control, the heat insulation layer can play a thermal insulation barrier effect, prevent the heat dissipation and safety needs of the power battery.
Smart Images
Figure CN222735117U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of thermal runaway of power batteries, and in particular to a power battery heat insulation component and a power battery pack. Background Art
[0002] Electric vehicles account for an increasingly larger proportion of the automotive market. The power batteries of electric vehicles are prone to thermal runaway due to their own characteristics and usage environment. Thermal runaway can cause thermal damage to the power batteries, leading to spontaneous combustion or even explosion of the vehicle. Spontaneous combustion not only brings economic losses to users, but also spreads to other high-voltage systems due to failure to extinguish the fire in time, causing combustion and explosion, and causing harm to nearby vehicles and flammable items. Therefore, the safety of power batteries has become an issue of increasing concern to everyone.
[0003] In the related art, in order to prevent the spread of thermal runaway, thermal insulation materials are usually installed between battery modules. Generally, thermal insulation materials are used to separate each battery cell in a power battery module or battery pack. However, the battery cell will generate heat during operation. The thermal conductivity of the thermal insulation material is low, which increases the heat dissipation problem of the battery cell during operation, and the battery cell cannot dissipate heat during operation. Utility Model Content
[0004] In view of the above shortcomings of the prior art, the purpose of the present application is to provide a power battery thermal insulation component and a power battery pack, which are used to solve the problem that the thermal insulation materials of the power battery in the prior art cannot take into account both thermal insulation and heat dissipation.
[0005] In order to achieve the above-mentioned purpose and other related purposes, the present application provides a power battery thermal insulation component, including:
[0006] Insulation layer;
[0007] The heat-conducting layer is arranged on the upper surface and the lower surface of the heat-insulating layer. The heat-conducting layer comprises a heat-conducting matrix and heat-conducting fibers. The heat-conducting fibers are distributed in the heat-conducting matrix and are interwoven in the heat-conducting matrix to form a three-dimensional network structure.
[0008] Optionally, the heat-conducting layer further includes flame-retardant particles, and the flame-retardant particles are distributed around the heat-conducting fibers.
[0009] Optionally, the flame retardant particles are halogen flame retardants or inorganic flame retardants.
[0010] Optionally, the thermally conductive fiber is a linear structure.
[0011] Optionally, the thermally conductive fiber is one of carbon fiber, carbon nanotube fiber, and graphite fiber.
[0012] Optionally, a release layer is further provided on a side of the heat-conducting layer away from the heat-insulating layer.
[0013] Optionally, the heat insulation layer includes a heat insulation matrix, the heat insulation matrix is aerogel, and the heat conductive matrix is heat conductive glue.
[0014] Optionally, at least two heat-conducting layers are provided, and the heat-conducting layers and the heat-insulating layer are arranged flush with each other on both sides in the length direction.
[0015] Optionally, the thickness of the thermal insulation layer is 1-2 mm.
[0016] Based on the same utility model concept, the present application also provides a power battery pack, including:
[0017] A plurality of battery cells connected in series or in parallel;
[0018] And the power battery heat insulation component as described above, wherein the power battery heat insulation component is arranged between at least two battery cells.
[0019] In the power battery thermal insulation component provided in the present application, during the normal operation of the battery cell, the heat generated by the battery cell is conducted away through the thermal conductive fibers in the thermal conductive matrix to dissipate the heat of the battery cell, so that the heat generated by the battery cell during operation can be dissipated in time to achieve a good heat dissipation effect. When thermal runaway of the battery occurs, the thermal insulation layer can also play a heat insulation barrier effect to prevent the spread of thermal runaway, and can simultaneously meet the heat dissipation requirements of the power battery during normal operation and the safety requirements during thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is a schematic structural diagram of a power battery heat insulation component according to an embodiment of the present application;
[0021] Figure 2 for Figure 1 Schematic diagram of the structure of the heat conducting layer in FIG.
[0022] Figure 3 This is a schematic diagram of the structure of a power battery pack according to an embodiment of the present application.
[0023] Part Number Description
[0024] 1-power battery pack; 11-battery unit; 12-thermal insulation; 121-thermal insulation layer; 122-thermal conductive layer; 1221-three-dimensional mesh structure; 1222-flame retardant particles. DETAILED DESCRIPTION
[0025] The following is an explanation of the implementation of the present application by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification.
[0026] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions that can be implemented in this application, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed in this application without affecting the effects that can be produced by this application and the purposes that can be achieved. At the same time, the terms such as "front", "back", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of narration, and are not used to limit the scope of the implementation of this application. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of this application without substantial changes in the technical content.
[0027] See also Figures 1 to 3 , the present application exemplarily provides a power battery heat insulation component, including:
[0028] Thermal insulation layer 121;
[0029] The heat-conducting layer 122 is arranged on the upper surface and the lower surface of the heat-insulating layer 121 . The heat-conducting layer 122 includes a heat-conducting matrix and heat-conducting fibers. The heat-conducting fibers are distributed in the heat-conducting matrix. The heat-conducting fibers are interwoven in the heat-conducting matrix to form a three-dimensional network structure 1221 .
[0030] In the power battery thermal insulation component provided in the present application, during the normal operation of the battery cell 11, the heat generated by the battery cell 11 is conducted away through the thermal conductive fibers in the thermal conductive matrix to dissipate the heat of the battery cell 11, so that the heat generated by the battery cell 11 during operation can be dissipated in time to achieve a good heat dissipation effect. When thermal runaway of the battery occurs, the thermal insulation layer 121 can also play a heat insulation barrier effect to prevent the spread of thermal runaway, and can simultaneously meet the heat dissipation requirements of the power battery during normal operation and the safety requirements during thermal runaway.
[0031] It should be noted that in order to solve the problem of thermal runaway propagation in battery packs, thermal protection is usually set between battery cells, between battery modules, and between the battery box and the passenger compartment to increase the thermal resistance of heat transfer from the thermal runaway battery cells to other battery systems, thereby achieving the purpose of hindering the spread of thermal runaway. Aerogel insulation materials are generally used to separate each battery cell in the power battery module or battery pack. When in use, double-sided tape is usually affixed to the aerogel pad. Due to the low thermal conductivity of aerogel and ordinary double-sided tape, this increases the heat dissipation problem of the battery cell during operation. In addition, aerogel materials are usually made by mixing aerogel particles and other materials and bonding them with adhesives. They are not stable and have limited thermal insulation properties.
[0032] In this embodiment, if Figure 1 and Figure 2As shown, the thermal conductive layer 122 also includes flame retardant particles 1222, which are distributed around the thermal conductive fibers. When the battery is working normally, the flame retardant particles 1222 will not affect the thermal conductive effect of the thermal conductive fibers on the battery cell 11. In the event of high-temperature thermal runaway, the flame retardant particles 1222 dispersed around the thermal conductive fibers can quickly absorb heat to avoid heat accumulation, thereby achieving the effect of thermal insulation and flame retardancy. Combined with the thermal insulation layer 121, the thermal insulation and flame retardancy are better, more stable, and safer.
[0033] Specifically, the flame retardant particles 1222 are halogen flame retardants or inorganic flame retardants. Halogen flame retardants include organic bromine flame retardants. Inorganic flame retardants include at least one of antimony trioxide, iron oxide, and zinc borate. These types of flame retardant particles 1222 have high flame retardant efficiency, good compatibility with thermal conductive substrates and thermal conductive fibers, and can be evenly dispersed in the three-dimensional network structure 1221.
[0034] In detail, the particle size of the flame retardant particles 1222 is 1-20 μm. Such a particle size allows the flame retardant particles 1222 to be fully dispersed into the gaps in the three-dimensional network structure 1221, while ensuring the flame retardant effect without significantly improving the physical properties of the material, forming a denser structure, and being able to further improve the heat transfer flame retardant effect during thermal runaway.
[0035] In the present embodiment, the thermal conductive fiber is a linear structure, the diameter of the thermal conductive fiber is 3-500 μm, and the length is 0.1-100 mm. Specifically, a reasonable setting of the diameter of the thermal conductive fiber can ensure that the thermal conductive fibers are interwoven to form a three-dimensional network structure 1221, which can play a good thermal conductive role. If the thermal conductive fiber is too thick, the formability and processability may be reduced. A reasonable setting of the length of the thermal conductive fiber can improve the strength of the three-dimensional network structure 1221. If the length of the thermal conductive fiber is too short, the shape retention and mechanical strength of the three-dimensional network structure 1221 will be reduced.
[0036] In detail, the thermal conductive fiber is one of carbon fiber, carbon nanotube fiber, and graphite fiber. The carbon-based fiber has higher thermal conductivity and higher thermal conductivity efficiency. The battery cell 11 expands and contracts in volume during the charge and discharge process. The carbon-based fiber has good mechanical properties to resist deformation and can maintain good thermal conductivity during the cycle, thereby increasing the service life of the thermal insulation 12.
[0037] In some embodiments, the pore size of the three-dimensional mesh structure 1221 is 20μm-5mm, and the porosity is 20-95%. The flame retardant particles 1222 are accommodated by the three-dimensional mesh structure 1221, so that the flame retardant particles 1222 are dispersed around the thermal conductive fibers. When the battery thermally runs away, the three-dimensional mesh structure 1221 forms a heat conductive channel to promote the dissipation of heat from the battery cell 11. At the same time, the heat can be quickly absorbed by the flame retardant particles 1222 to prevent the heat from further spreading to other battery cells 11.
[0038] Specifically, the thermal insulation layer 121 includes a thermal insulation matrix, the thermal insulation matrix is aerogel, and the thermal conductive matrix is thermal conductive glue. The thermal insulation layer 121 formed by using aerogel as the thermal insulation matrix has good buffering and thermal insulation properties, and can adapt to the volume expansion of the battery cell 11 during the charging and discharging process of the battery module, thereby extending the life of the battery module. The thermal conductive layer 122 formed by using thermal conductive glue as the thermal conductive matrix has self-adhesiveness to connect the thermal insulation layer 121 and the battery cell 11.
[0039] In detail, the aerogel is a single-component aerogel, and the material of the aerogel is one of SiO2, ZrO2, and Al2O3. Using aerogel as an insulating matrix has good buffering and thermal insulation properties, and the thermal conductivity is 0.012-0.024W / (m·K). It can adapt to the volume expansion of the battery cell 11 during the charging and discharging process of the battery module and extend the life of the battery module. At the same time, it has excellent thermal insulation performance and effectively hinders heat transfer when the battery cell 11 thermally runs away.
[0040] In some embodiments, the aerogel may also be a multi-component aerogel, such as Al2O3 / SiO2, TiO2 / SiO2, Fe / SiO2, Pt / TiO2, etc., and the thermal conductive adhesive may be a viscous material such as polyurethane adhesive, epoxy resin adhesive, etc. The materials of the aerogel and the thermal conductive adhesive are not limited herein.
[0041] It can be understood that in order to ensure that the thermal conductive fibers and flame retardant particles 1222 in the thermal conductive layer 122 are fully and evenly dispersed, a dispersant is also added to the thermal conductive layer 122 during the preparation process, which effectively improves the dispersion uniformity of the thermal conductive fibers and flame retardant particles 1222 in the thermal conductive matrix, thereby helping the thermal conductive fibers to form a three-dimensional network structure 1221. The flame retardant particles 1222 dispersed around the thermal conductive fibers can quickly absorb heat and have a flame retardant effect.
[0042] In this embodiment, if Figure 1 and Figure 3 As shown, at least two heat-conducting layers 122 are provided, and the heat-conducting layers 122 and the heat-insulating layers 121 are arranged flush with each other on both sides in the length direction. The heat-conducting layers 122 and the heat-insulating layers 121 are arranged flush with each other to ensure that the heat-conducting layers 122 connect the heat-insulating layers 121 to the battery cells 11, and the heat-conducting layers 122 are in full contact with the battery cells 11, so that the heat generated by the battery cells 11 can be timely conducted by the heat-conducting layers 122, which can not only dissipate heat and reduce the requirements for cooling the battery module, but also provide insulation in the event of thermal runaway to prevent the thermal runaway from spreading.
[0043] It can be understood that the heat conductive layer 122 is also provided with a release layer on the side away from the heat insulating layer 121. Having a release layer when manufacturing the thermal insulation component 12 is conducive to large-scale production and transportation. When assembling the battery module, the thermal insulation component 12 is cut according to the required size and dimensions, and the release layer is peeled off, so that the thermal insulation component 12 can be bonded to the battery cell 11.
[0044] In this embodiment, the thickness of the thermal insulation layer 121 is 1-2 mm, the thickness of the thermal conductive layer 122 is 1-2 mm, and the overall thickness of the thermal insulation component 12 is 2-4 mm. The thinner structure is not easy to fall off, so that the battery unit 11 can dissipate heat well. While ensuring the heat dissipation performance, it can also effectively suppress heat transfer during thermal runaway. In addition, the thermal insulation component 12 occupies a small space, reducing the battery module's requirements for the cooling system, allowing the battery module to have more layout space, thereby further increasing the battery capacity.
[0045] In another embodiment, if Figure 3 As shown, the present application also provides a power battery pack 1, comprising:
[0046] A plurality of battery cells 11 connected in series or in parallel;
[0047] And the battery heat insulation 12 mentioned above, the battery heat insulation 12 is arranged between at least two battery cells 11.
[0048] In this embodiment, the thermal insulation member 12 is configured to be plate-shaped to ensure uniform thickness, which is beneficial to the uniformity of heat dissipation and thermal insulation between the battery cells 11. The shape of the thermal insulation member 12 can be adjusted according to the shape of the battery cell 11, and the shape of the thermal insulation member 12 is not limited here.
[0049] Specifically, the cross-sectional area of the thermal insulation 12 in the direction perpendicular to its thickness is the same as the cross-sectional area of the battery cell 11 on one side thereof that is in contact with the thermal insulation 12, so that the thermal insulation 12 can cover all contact surfaces between adjacent battery cells 11 in the power battery pack 1, thereby improving the heat dissipation effect of the power battery pack 1 under normal operation and the thermal insulation effect under thermal runaway. During normal use, since the battery cell 11 is in direct contact with the thermal conductive layer 122, the heat generated by the battery cell 11 is conducted away through the thermal conductive layer 122. In the event that a battery cell 11 catches fire, the flame retardant particles 1222 in the thermal conductive layer 122 and the thermal insulation layer 121 can suppress the flame from spreading to adjacent battery cells 11.
[0050] In summary, in the power battery thermal insulation component provided in the present application, during the normal operation of the battery cell 11, the heat generated by the battery cell 11 is conducted away through the thermal conductive fibers in the thermal conductive matrix to dissipate the heat of the battery cell 11, so that the heat generated by the battery cell 11 during operation can be dissipated in time to achieve a good heat dissipation effect. When thermal runaway of the battery occurs, the thermal insulation layer 121 can also play a heat insulation barrier effect to prevent the spread of thermal runaway, and can simultaneously meet the heat dissipation requirements of the power battery during normal operation and the safety requirements during thermal runaway.
[0051] The above embodiments are merely illustrative of the principles and effects of the present application, and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.
Claims
1. A power battery heat insulation component, characterized in that: include: Insulation layer; The heat-conducting layer is arranged on the upper surface and the lower surface of the heat-insulating layer. The heat-conducting layer comprises a heat-conducting matrix and heat-conducting fibers. The heat-conducting fibers are distributed in the heat-conducting matrix and are interwoven in the heat-conducting matrix to form a three-dimensional network structure.
2. The power battery heat insulation component according to claim 1, characterized in that: The heat-conducting layer further comprises flame-retardant particles, and the flame-retardant particles are distributed around the heat-conducting fibers.
3. The power battery heat insulation component according to claim 2, characterized in that: The flame retardant particles are halogen flame retardants or inorganic flame retardants.
4. The power battery heat insulation component according to claim 1, characterized in that: The thermally conductive fiber is a linear structure.
5. The power battery heat insulation component according to claim 1, characterized in that: The thermally conductive fiber is one of carbon fiber, carbon nanotube fiber and graphite fiber.
6. The power battery heat insulation component according to claim 1, characterized in that: The heat-conducting layer is further provided with a release layer on a side away from the heat-insulating layer.
7. The power battery heat insulation component according to claim 1, characterized in that: The heat insulation layer comprises a heat insulation matrix, the heat insulation matrix is aerogel, and the heat conductive matrix is heat conductive glue.
8. The power battery heat insulation component according to claim 1, characterized in that: At least two heat-conducting layers are provided, and the heat-conducting layers and the heat-insulating layers are arranged flush with each other on both sides in the length direction.
9. The power battery heat insulation component according to claim 1, characterized in that: The thickness of the heat insulation layer is 1-2 mm.
10. A power battery pack, characterized in that: include: A plurality of battery cells connected in series or in parallel; And the power battery heat insulation component according to any one of claims 1 to 9, wherein the power battery heat insulation component is arranged between at least two battery cells.