Battery cell temperature equalizing piece, energy storage module and energy storage device

Abstract

The utility model provides a battery cell temperature equalizing piece, an energy storage module and an energy storage device. The cell temperature equalizing piece comprises a heat insulation material layer, a phase change material layer, a first packaging film and a second packaging film, the heat insulation material layer is packaged in the first packaging film, the phase change material layers are located on the two sides of the heat insulation material layer, the phase change material layers on the two sides abut against the first packaging film, and the phase change material layers on the two sides, the first packaging film and the heat insulation material layer are packaged into a whole through the second packaging film. According to the battery cell temperature equalizing piece, the heat insulation material layer is arranged in the middle and the phase change material layers are arranged on the two sides of the heat insulation material layer, so that the heat transfer of the battery cell is facilitated, the temperature equalizing property in the battery cell is improved, the spreading of thermal runaway of the battery cell can be inhibited, and a good use effect is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage batteries, and in particular to a battery core temperature equalizing component. The utility model also relates to an energy storage module provided with the battery core temperature equalizing component. Background Art

[0002] During the battery charging and discharging process, heat will be generated inside. If the heat generated by the battery cell cannot be transferred out in time, the heat will cause accumulation inside the battery cell, which will in turn cause changes in the battery cell temperature. When the temperature exceeds a certain limit, it will lead to intensified electrochemical side reactions in the battery cell and even instability of the active materials, ultimately affecting the performance and safety of the battery cell.

[0003] At present, the energy storage system adopts the method of installing aerogel between the module cells to safely protect the battery cells from thermal runaway. Its thermal insulation performance is excellent, but its disadvantages are also obvious: when the battery cell thermal runaway occurs, it only has a thermal insulation effect, and the heat generated by the thermal runaway battery cell cannot be effectively released to the external environment, resulting in a high temperature of the runaway battery cell, and it is impossible to effectively suppress the thermal runaway of the adjacent battery cell. In normal operation, it has a heat preservation effect on the battery cell. Thermal management requires more flow and flow channels to reduce the temperature of the battery cell, and the heat preservation effect will increase the temperature difference of the single battery cell in the pack, affecting the cycle. Utility Model Content

[0004] In view of this, the utility model aims to provide a battery cell temperature equalizing component to facilitate the transfer of heat from the battery cell, improve the temperature uniformity inside the battery cell, and inhibit the spread of thermal runaway of the battery cell.

[0005] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0006] A battery core temperature equalizing member, comprising a heat insulation material layer, a phase change material layer, and a first packaging film and a second packaging film;

[0007] The thermal insulation material layer is encapsulated in the first packaging film, the phase change material layer is located on both sides of the thermal insulation material layer, the phase change material layers on both sides are abutted against the first packaging film, and the phase change material layers on both sides, the first packaging film and the thermal insulation material layer are encapsulated into one by the second packaging film.

[0008] Furthermore, the thermal insulation material layer is made of one of aerogel pad, thermal insulation foam and thermal insulation ceramic paper.

[0009] Furthermore, the phase change material layer is made of paraffin.

[0010] Furthermore, the first packaging film is made of PET film, PE film or Teflon tape.

[0011] Furthermore, the second packaging film is a PI film.

[0012] Furthermore, the thickness of the heat insulation material layer is between 0.1 mm and 1 mm, and / or the thickness of the phase change material layer is between 0.1 mm and 1 mm.

[0013] Furthermore, the second packaging film has a packaging end, a weak packaging portion is provided on the packaging end, and a packaging width d2 of the weak packaging portion is smaller than a packaging width d1 of the packaging end.

[0014] Furthermore, the projection of the weak packaging portion on the thermal insulation material layer is U-shaped.

[0015] Compared with the prior art, the utility model has the following advantages:

[0016] The battery cell temperature equalizing member described in the utility model is provided with a heat-insulating material layer and a phase-change material layer provided on both sides of the heat-insulating material layer, so that the heat generated by the battery cell during operation is absorbed by the phase-change material, the temperature is controlled within the melting point, the auxiliary thermal management system balances the battery cell temperature, reduces heat accumulation, reduces the maximum temperature of the battery cell, and reduces the thermal management cost. After the working cycle is completed, the phase-change material cools and solidifies, and the phase change of the phase-change material is used to achieve the effect of temperature uniformity and heat dissipation. Moreover, when the battery cell is thermally runaway, the rapid gasification and eruption of the phase-change materials on both sides are used to bring out the heat, and at the same time, the heat-insulating material layer in the middle can effectively prevent the spread of thermal runaway.

[0017] In addition, the thermal insulation material layer uses one of aerogel pads, thermal insulation foam and thermal insulation ceramic paper, which has good fireproof and thermal insulation properties. The phase change material layer uses paraffin, which has a melting point between 30-35°C and a boiling point between 300-500°C. When the battery cell is working, the temperature rises and the heat is absorbed by the phase change material, so that the temperature is controlled within the melting point. Before the battery cell reaches thermal runaway, the phase change material begins to boil and absorbs heat to vaporize. At this time, the pressure inside the cavity where the phase change material is located increases. When it is squeezed by the battery cell to the critical point, the gas breaks through the second packaging film and takes away part of the heat before the battery cell runs out of control, thereby slowing down the severity of the runaway and reducing the maximum temperature during thermal runaway. At the same time, when the phase change material vaporizes and breaks through the packaging and is discharged to the outside, it also releases a certain amount of space for the battery cell. The battery cell expands outward to release part of the internal pressure, which can effectively alleviate the severity of the internal reaction.

[0018] In addition, the first packaging film adopts PET film, PE film or Teflon tape, which has good high temperature resistance and insulation performance, which is beneficial to blocking the transmission of thermal runaway. The second packaging film adopts PI film, which has a certain elastic deformation force and the advantage of high temperature resistance, which is beneficial to improve the use effect of phase change material. The thickness of the insulation material layer and the thickness of the phase change material layer are limited, so that the overall thickness of the battery cell temperature equalizer is thin, which is beneficial to improve the energy density of the energy storage module. A weak packaging part is set on the packaging end, which can facilitate the directional discharge of the vaporized phase change material in the event of thermal runaway. The weak packaging part is U-shaped, with a simple structure and easy processing and molding.

[0019] Another object of the present utility model is to provide an energy storage module, in which a battery cell temperature equalizing member as described in the first embodiment is provided between two adjacent battery cells.

[0020] Another object of the present invention is to provide an energy storage device, in which the energy storage module as described above is provided.

[0021] The energy storage module and energy storage device of the present invention can improve the temperature uniformity inside the battery cell by adopting the above-mentioned battery cell temperature equalizing component, and can effectively suppress the spread of thermal runaway of the battery cell, thereby helping to improve the safety factor and service life of the energy storage module, and also helping to improve the safety factor and service life of the energy storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0023] Figure 1 This is a schematic diagram of the structure of the battery core temperature equalizing member according to an embodiment of the utility model;

[0024] Figure 2 This is a structural schematic diagram of the package weak portion according to an embodiment of the utility model;

[0025] Figure 3 This is a schematic diagram of the structure of the energy storage module according to an embodiment of the utility model;

[0026] Description of reference numerals:

[0027] 1. Thermal insulation material layer; 2. Phase change material layer; 3. First packaging film; 4. Second packaging film; 5. Battery cell; 10. Temperature equalizer. DETAILED DESCRIPTION

[0028] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0029] In the description of the present invention, it should be noted that if there are terms such as "upper", "lower", "inner", "outer" and the like indicating orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention 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 limiting the present invention. In addition, if there are terms such as "first" and "second", they are also used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0030] In addition, in the description of the present invention, unless otherwise clearly defined, the terms "installation", "connection", "connection" and "connector" 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 or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood in combination with specific circumstances.

[0031] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0032] Embodiment 1

[0033] The present embodiment relates to a battery cell temperature equalizing member 10 , which is beneficial to the transfer of heat of the battery cell 5 , improves the temperature uniformity inside the battery cell 5 , and can inhibit the spread of thermal runaway of the battery cell 5 .

[0034] In terms of overall structure, the battery cell temperature equalizing member 10 of this embodiment is as follows: Figure 1 As shown, the battery cell temperature equalizing member 10 includes a heat insulating material layer 1 , a phase change material layer 2 , and a first packaging film 3 and a second packaging film 4 .

[0035] Among them, the thermal insulation material layer 1 is encapsulated in the first packaging film 3, the phase change material layer 2 is located on both sides of the thermal insulation material layer 1, the phase change material layer 2 on both sides abuts against the first packaging film 3, and the phase change material layer 2 on both sides, the first packaging film 3 and the thermal insulation material layer 1 are encapsulated into one by the second packaging film 4.

[0036] At this time, the setting of the heat-insulating material layer 1 and the deformation material layers on both sides allows the heat generated by the battery cell 5 during operation to be absorbed by the phase-change material, controlling the temperature within the melting point, assisting the thermal management system to balance the temperature of the battery cell 5, reducing heat accumulation, lowering the maximum temperature of the battery cell 5, and reducing the thermal management cost. After the work cycle is completed, the phase-change material cools and solidifies, and the phase change of the phase-change material is used to achieve the effect of uniform temperature and heat dissipation. Moreover, when the battery cell 5 is thermally runaway, the rapid vaporization and eruption of the phase-change materials on both sides are used to take out the heat, and at the same time, the heat-insulating material layer 1 in the middle can effectively prevent the spread of thermal runaway.

[0037] Specifically, combined with Figure 1 to Figure 2 As shown, as a preferred embodiment, in this embodiment, the thermal insulation material layer 1 is one of aerogel pad, thermal insulation foam and thermal insulation ceramic paper. In this way, the fireproof and heat-insulating properties of aerogel pad, thermal insulation foam or thermal insulation ceramic paper can be utilized to better block the transmission of thermal runaway.

[0038] In this embodiment, also as a preferred implementation, the phase change material layer 2 uses paraffin. At this time, the characteristics of paraffin melting point between 30-35°C and boiling point between 200-500°C are utilized, so that when the battery cell 5 is working, the temperature rises, and the heat is absorbed by the phase change material, so that the temperature is controlled within the melting point. Before the battery cell 5 reaches thermal runaway, the phase change material begins to boil, absorbs heat and vaporizes. At this time, the pressure inside the cavity where the phase change material is located increases. When it is squeezed by the battery cell 5 to the critical point, the gas breaks through the second packaging film 4 and takes away part of the heat before the battery cell 5 runs out of control, thereby slowing down the severity of the runaway and reducing the maximum temperature during thermal runaway. At the same time, when the phase change material vaporizes and breaks through the packaging and is discharged to the outside, it also releases a certain amount of space for the battery cell 5. The battery cell 5 expands outward to release part of the internal pressure, thereby effectively alleviating the severity of the internal reaction.

[0039] In this embodiment, the first packaging film 3 is preferably made of PET film, PE film or Teflon tape. The good high temperature resistance and insulation performance of PET film, PE film or Teflon tape are used to block the transmission of thermal runaway. In this embodiment, the second packaging film 4 is preferably made of PI film. It has a certain elastic deformation force and the advantages of high temperature resistance, which can help improve the use effect of phase change materials.

[0040] Also as a preferred embodiment, in this embodiment, the thickness of the thermal insulation material layer 1 is between 0.1mm and 1mm, and the thickness of the phase change material layer 2 is between 0.1mm and 1mm. By limiting the thickness of the thermal insulation material layer 1 and the thickness of the phase change material layer 2, the overall thickness of the battery cell temperature equalizer 10 is thinner, which is conducive to improving the energy density of the energy storage module.

[0041] It should be noted that, in addition to setting the thickness of both the heat insulation material layer 1 and the phase change material layer 2, it is also possible to set only the thickness of the heat insulation material layer 1, or only the thickness of the phase change material layer 2. In addition, it should be noted that the thermal conductivity of the heat insulation material layer 1 of this embodiment is ≤0.020W / (m·k). In addition to paraffin, the phase change material can also be the phase change material S series used in the floor system, which needs to meet the melting point between 30-35°C and the boiling point between 200-500°C.

[0042] In this embodiment, the second packaging film 4 has a packaging end, and a weak packaging portion is provided on the packaging end. The packaging width d2 of the weak packaging portion is smaller than the packaging width d1 of the packaging end. The provision of the weak packaging portion can facilitate the directional discharge of the vaporized phase change material in the event of thermal runaway. As a preferred embodiment, Figure 2 As shown, the projection of the weak packaging part on the heat insulation material layer 1 is U-shaped, so the structure is simple and easy to process and shape.

[0043] In the specific preparation of the battery cell temperature equalizing member 10 of this embodiment, the heat insulating material layer 1 is first encapsulated in the first encapsulation film 3, and then the phase change material layer 2 and the heat insulating material layer 1 encapsulated with the first encapsulation film 3 are encapsulated in the second encapsulation film 4. When encapsulating the second encapsulation film 4, a roughly encapsulated boundary can be firstly heat-pressed, and then a second precise heat-pressing edge sealing can be performed. During the second heat-pressing packaging, a weak encapsulation portion is reserved to complete the battery cell temperature equalizing member 10.

[0044] The temperature of the battery cell when it is judged to be out of control is usually around 90-130℃, and the subsequent continuous temperature rise of the battery cell will exceed 500℃. Before the battery cell reaches thermal runaway, the phase change material begins to boil, absorbs heat and vaporizes, and the pressure inside the cavity where the phase change material layer 2 is located increases. When both sides of the battery cell temperature equalizer 10 are squeezed by the battery cell 5 to the critical point, they will be discharged from the weak packaging part in a directional manner, and the path is as follows: Figure 2 as shown in .

[0045] During the discharge process, part of the heat before the cell loses control is taken away, thereby reducing the severity of the loss of control and lowering the maximum temperature during the loss of control. The middle heat-insulating material layer 1 can effectively inhibit heat diffusion. Moreover, when the phase-change material vaporizes and breaks through the weak packaging part to be discharged to the outside, a certain space is also released for the cell 5. The cell 5 expands outward to release part of the internal pressure, which can also effectively reduce the severity of the internal reaction. By taking advantage of the fact that the larger the external expandable space, the smaller the internal reaction of the cell 5, the maximum temperature of the triggered cell 5 can also be reduced, achieving the effect of consistent heat diffusion.

[0046] The battery cell temperature equalizing member 10 of the present embodiment can improve the temperature uniformity inside the battery cell 5 and can effectively suppress the spread of thermal runaway of the battery cell 5 , and has a good use effect.

[0047] Embodiment 2

[0048] This embodiment relates to an energy storage module, such as Figure 3 As shown, in the energy storage module, the cell temperature equalizing member 10 described in the first embodiment is provided between two adjacent cells 5. In addition, at least one side of the energy storage module is also provided with a liquid cooling plate, which is bonded to the energy storage module by a heat-conducting structural adhesive. At this time, the cooperation between the cell temperature equalizing member 10 and the liquid cooling plate can further improve the temperature uniformity of the energy storage module.

[0049] This embodiment also relates to an energy storage device, in which the above energy storage module is provided.

[0050] The energy storage module and energy storage device of this embodiment, by adopting the above-mentioned battery cell temperature equalizing member 10, can slow down the temperature rise rate of the battery cell 5, improve the thermal management efficiency, and reduce the temperature difference of the internal battery cell 5 when the energy storage system is running. Moreover, when a single battery cell 5 in the energy storage module has thermal runaway, the heat of the triggering battery cell 5 is taken away by the eruption of the phase change material, and a certain expansion space can be vacated to reduce the maximum temperature when the triggering battery cell 5 is out of control, thereby inhibiting the spread of thermal runaway, thereby facilitating the improvement of the safety factor and service life of the energy storage module, and also facilitating the improvement of the safety factor and service life of the energy storage device.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery cell temperature equalizing component, characterized in that: It includes a heat-insulating material layer, a phase-change material layer, a first packaging film and a second packaging film; The thermal insulation material layer is encapsulated in the first packaging film, the phase change material layer is located on both sides of the thermal insulation material layer, the phase change material layers on both sides are abutted against the first packaging film, and the phase change material layers on both sides, the first packaging film and the thermal insulation material layer are encapsulated into one by the second packaging film.

2. The battery core temperature equalizing member according to claim 1, characterized in that: The thermal insulation material layer is one of aerogel pad, thermal insulation foam and thermal insulation ceramic paper.

3. The battery core temperature equalizing member according to claim 1, characterized in that: The phase change material layer is made of paraffin.

4. The battery core temperature equalizing member according to claim 1, characterized in that: The first packaging film is made of PET film, PE film or Teflon tape.

5. The battery cell temperature equalizing member according to claim 1, characterized in that: The second packaging film is a PI film.

6. The battery cell temperature equalizing member according to claim 1, characterized in that: The thickness of the heat insulation material layer is between 0.1 mm and 1 mm, and / or the thickness of the phase change material layer is between 0.1 mm and 1 mm.

7. The battery cell temperature equalizing element according to any one of claims 1 to 6, characterized in that: The second packaging film has a packaging end, a weak packaging portion is provided on the packaging end, and a packaging width d2 of the weak packaging portion is smaller than a packaging width d1 of the packaging end.

8. The battery cell temperature equalizing member according to claim 7, characterized in that: The projection of the weak packaging portion on the heat insulation material layer is U-shaped.

9. An energy storage module, characterized in that: In the energy storage module, a cell temperature equalizing member according to any one of claims 1 to 8 is provided between two adjacent cell elements.

10. An energy storage device, characterized in that: The energy storage device is provided with the energy storage module described in claim 9.

Images