Insulating film, battery, and battery module
By introducing a thermally conductive layer and an electric heating element into the insulating film, combined with PTC material and coating process, the problem that existing insulating films cannot manage cell temperature is solved, realizing controllable heating and heat management of the cell temperature, and improving battery safety and lifespan.
Patent Information
- Application Number
- CN202423061218.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-11
- Publication Date
- 2026-01-06
- Estimated Expiration
- 2034-12-11
AI Technical Summary
Existing insulating films have a single function, mainly serving as insulation, and cannot effectively manage the temperature of the battery cell, resulting in performance degradation at low temperatures or safety hazards at high temperatures.
Design an insulating film comprising a thermally conductive layer and an insulating layer. The thermally conductive layer contains an electric heating element that can be independently controlled by multiple electrodes to achieve zoned heating and heat management. It is manufactured using PTC material and insulating layer materials with different Curie temperatures, combined with a coating process.
It enables controllable heating and thermal management of the battery cell temperature, improving battery safety and lifespan while reducing the space occupied by the battery assembly.
Smart Images
Figure CN223770893U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, and in particular to an insulating film, a battery, and a battery assembly. Background Technology
[0002] The outer casing of the battery cell is usually made of pure aluminum or stainless steel. To provide insulation protection for the battery cell, the outer casing is usually covered with an insulating film. The main function of the insulating film is to ensure the safety of the battery cell during storage, transportation, assembly and grouping, and to prevent short circuits or explosions caused by contact between battery cells.
[0003] However, the insulating film in the existing technology has a single function, usually mainly serving as insulation, and there is room for improvement. Utility Model Content
[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes an insulating film whose thermally conductive layer has good thermal conductivity and heating properties. When the battery cell temperature rises, it can effectively transfer heat, and when the battery cell temperature is too cold, it can heat the battery cell, thus integrating insulation and heating functions. Simultaneously, the electric heating unit includes multiple electrodes that supply power to sub-thermally conductive layers of the thermally conductive layer, and each electrode can be independently controlled to achieve zoned heating of the sub-thermally conductive layers.
[0005] An insulating film according to an embodiment of the present invention includes: at least two insulating layers and a thermally conductive layer, wherein the thermally conductive layer is disposed between two of the insulating layers, and an electric heating part is provided within the thermally conductive layer, the electric heating part being adapted to be connected to an external power source; the thermally conductive layer includes two sub-thermally conductive layers, the electric heating part being located between the two sub-thermally conductive layers, and each of the two sub-thermally conductive layers is connected to an insulating layer on the side away from each other; the two sub-thermally conductive layers are symmetrical about the electric heating part; the electric heating part includes a plurality of spaced electrodes, one end of the plurality of electrodes is connected to the positive terminal of the external power source, and the other end is connected to the negative terminal of the external power source, each electrode can be independently connected to an external power source, realizing independent control of each electrode to heat the sub-thermally conductive layers in sections.
[0006] According to the insulating film of this utility model embodiment, one insulating layer is used to connect with the battery cell, and the other layer is exposed to the outside, so as to insulate the battery cell from the external environment. A heat-conducting layer is provided between the two insulating layers. When the battery cell temperature is too low, the heat-conducting layer has a heating function to heat the battery cell and keep it warm. When the battery cell temperature is too high, the heat-conducting layer can effectively dissipate heat. At the same time, the electric heating part includes multiple electrodes, which supply power to the sub-heat-conducting layers of the heat-conducting layer. Each electrode can be independently controlled to realize the zoned heating of the sub-heat-conducting layers.
[0007] According to the insulating film of this utility model embodiment, the sub-thermal conductive layer is made of PTC material.
[0008] According to the insulating film of the present invention, the insulating layer can be selectively made of PET material according to the different Curie temperatures of the sub-thermal conductive layer.
[0009] According to an embodiment of the present invention, at least one of the insulating layers has a tearable centrifugal layer attached to its outer side.
[0010] According to the insulating film of the present invention, the thermally conductive layer is disposed on the insulating film by coating.
[0011] This utility model discloses a battery, including a battery cell and the above-mentioned insulating film, wherein the insulating film covers the outside of the battery cell.
[0012] This utility model embodiment also discloses a battery assembly, including a plurality of the above-described batteries, wherein the plurality of insulating films of the plurality of batteries are connected in series through the electric heating part.
[0013] According to the battery assembly of this utility model embodiment, multiple insulating films of multiple batteries are electrically connected. Thus, the heat-conducting layer in the multiple electrically connected insulating films can simultaneously heat and conduct heat to multiple battery cells, thereby improving the performance of the entire battery assembly.
[0014] According to the battery assembly of this utility model embodiment, each of the battery cells is covered with one layer of the insulating film along a first direction and another layer of the insulating film along a second direction, and the electric heating parts between the insulating films of adjacent batteries are connected in series.
[0015] According to the battery assembly of this utility model embodiment, the same side of a plurality of batteries includes an electric heating portion with the same extending direction, and the extending direction of the electric heating portion is consistent with the arrangement direction of the plurality of batteries, and adjacent batteries are electrically connected through adjacent electric heating portions.
[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0017] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0018] Figure 1 This is a schematic diagram of the internal structure layer of the insulating film according to an embodiment of the present invention;
[0019] Figure 2 This is a schematic diagram showing the positional relationship between the insulating film and the battery cell in an embodiment of this utility model;
[0020] Figure 3 This is a schematic diagram of the structure of multiple insulating films connected in series according to an embodiment of the present invention;
[0021] Figure 4 This is a schematic diagram of the structure of the insulating film located at the bottom of multiple battery cells according to an embodiment of the present invention;
[0022] Figure 5 This is a schematic diagram of the structure of multiple insulating films of multiple battery cells connected in series in an embodiment of this utility model;
[0023] Figure 6 This is a schematic diagram of another series connection method between multiple insulating films of multiple battery cells according to an embodiment of the present invention;
[0024] Figure 7 This is an embodiment of the present utility model. Figure 6 An enlarged schematic diagram.
[0025] Figure label:
[0026] Insulating film 100,
[0027] Battery assembly 1000,
[0028] Insulating layer 1, thermally conductive layer 2, sub-thermally conductive layer 21, electrode 22, positive lead 221, negative lead 222, adhesive 3, double-sided adhesive 4, centrifugal layer 5, battery cell 6. Detailed Implementation
[0029] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.
[0030] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.
[0031] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0032] refer to Figures 1-7 According to the embodiment of the present invention, the insulating film 100 has two insulating layers 1. One insulating layer 1 is used to connect with the battery cell 6, and the other layer is exposed to the outside, so as to insulate the battery cell 6 from the external environment. A heat-conducting layer 2 is provided between the two insulating layers 1. When the temperature of the battery cell 6 is too low, the heat-conducting layer 2 has a heating function to heat the battery cell 6 and control the temperature of the battery cell 6. When the temperature of the battery cell 6 is too high, the heat-conducting layer 2 can effectively transfer the heat of the battery cell 6.
[0033] like Figure 1-7 As shown, an insulating film 100 according to an embodiment of the present invention includes: a thermally conductive layer 2 and at least two insulating layers 1.
[0034] The heat-conducting layer 2 is disposed between the two insulating layers 1, and an electric heating part is provided in the heat-conducting layer 2, which is suitable for being connected to an external power source.
[0035] In practice, one insulating layer 1 is used to connect with the surface of the battery cell 6, while the other insulating layer 1 is exposed on the outside to insulate the battery cell 6 from the external environment. The battery cell 6 can be a cylindrical cell, a square cell, or a long cell, so the shape of the insulating film 100 can vary with the shape of the battery cell 6. The thickness of each insulating layer 1 is between 0.05-0.2 mm, and a thicker insulating layer 1 can better achieve the wear resistance of the entire insulating film 100. The insulating layer 1 can be made of different materials, such as PET layer, PI layer, and PP layer. Non-metallic materials such as PET mainly consist of polyethylene terephthalate and polybutylene terephthalate, commonly known as polyester resin. PET is a condensation polymer of terephthalic acid and ethylene glycol, possessing excellent heat resistance and flame retardancy. The PI layer is a film or coating made of polyimide material. Its decomposition temperature generally exceeds 500℃, sometimes even higher, making it one of the most thermally stable known organic polymers. Polyimide materials are generally insoluble in organic solvents, corrosion-resistant, hydrolysis-resistant, and possess good chemical stability and resistance to damp heat. The PP layer refers to polypropylene, abbreviated as PP material, a semi-crystalline thermoplastic polymer made from propylene monomers through an addition polymerization reaction. It possesses good weather resistance, thermal properties, and high mechanical properties. In other words, all these insulating layers 1 have good heat resistance, so when the heat-conducting layer 2 is placed between the two insulating layers 1, the heat can be better dissipated, or when the heat-conducting layer 2 heats the insulating film 100, the insulating layer 1 maintains good performance within the set heating temperature range and is not easily deformed or damaged, thus achieving a better insulation effect.
[0036] The heat-conducting layer 2 is disposed between the two insulating layers 1. The heat-conducting layer 2 not only conducts heat but also conducts electricity. The electric heating element is located within the heat-conducting layer 2. When the electric heating element is electrically connected to an external power source, current is transferred to the heat-conducting layer 2 through the electric heating element, heating the heat-conducting layer 2. When the temperature of the battery cell 6 is too low, its performance will deteriorate. For example, low temperatures can affect the electrochemical reaction rate on the surface of the electrodes 22 inside the battery cell 6, leading to a slowdown in the charge and discharge rate. Therefore, heating the battery cell 6 through the heat-conducting layer 2 can improve the battery performance at low temperatures and increase the charge and discharge rate. Furthermore, placing the electric heating element inside the heat-conducting layer 2 improves the uniform heating effect of the heat-conducting layer 2, thus improving the temperature uniformity of the battery cell 6.
[0037] Therefore, by integrating the heat-conducting layer 2 between the two insulating layers 1, the insulating film 100 achieves both insulation and heating functions for the battery cell 6. Furthermore, when the temperature of the battery cell 6 is too high, the heat-conducting layer 2 can better transfer heat from the battery cell 6 to the outside, thereby improving the service life of the battery cell 6.
[0038] In some embodiments, the thermally conductive layer 2 includes two sub-thermally conductive layers 21, the electric heating part is located between the two sub-thermally conductive layers 21, and the two sub-thermally conductive layers 21 are respectively connected to an insulating layer 1 on the side away from each other.
[0039] Specifically, each sub-heat-conducting layer 21 can be bonded to the corresponding insulating layer 1 via an adhesive layer 3. The adhesive layer 3 is mainly resin adhesive, epoxy adhesive, or heat-sensitive adhesive, and its main function is to connect the insulating layer 1 and the heat-conducting layer 2 to achieve bonding. The electric heating part is located between the two sub-heat-conducting layers 21. The electric heating part realizes the connection between the two sub-heat-conducting layers 21 and the current flow. When the current passes through the electric heating part and is transferred to the sub-heat-conducting layers 21 on both sides, the temperature of the heat-conducting layers 2 is uniform. Thus, when the insulating film 100 is pasted on the surface of the battery cell 6, the effect of uniform temperature of the battery cell 6 can be achieved. When heating the battery cell 6, the heating temperature of the battery cell 6 can be made more uniform, and the phenomenon of local overheating can be avoided during the heat transfer of the battery cell 6.
[0040] In some embodiments, the two sub-thermal conductive layers 21 are symmetrical about the electric heating element.
[0041] The thickness of the electric heating element is between 0.01 and 0.1 mm, and the thickness of each sub-heat-conducting layer 21 is between 0.01 and 0.05 mm. The two sub-heat-conducting layers 21 are symmetrically arranged about the electric heating element, so the thickness of the two sub-heat-conducting layers 21 is set to be equal. When the current is transmitted to the sub-heat-conducting layers 21 through the electric heating element, the heating temperature between the two sub-heat-conducting layers 21 can be made more uniform. It can also avoid the temperature of one sub-heat-conducting layer 21 being too low and the temperature of the other sub-heat-conducting layer 21 being too high. That is, the temperature of the two sub-heat-conducting layers 21 is uniform. When it is necessary to heat the battery cell 6, the electric heating element can be energized to heat the sub-heat-conducting layers 21, and the sub-heat-conducting layers 21 then heat the battery cell 6. Thus, the sub-heat-conducting layers 21 closer to the battery cell 6 are heated first, and then the sub-heat-conducting layers 21 farther away from the battery cell 6 are heated, so as to achieve heating of the battery cell 6 layer by layer, thereby improving the uniformity of the heating temperature of the battery cell 6.
[0042] In some embodiments, the electric heating section includes a plurality of spaced electrodes 22, one end of which is connected to the positive terminal of an external power source, and the other end of which is connected to the negative terminal of the external power source.
[0043] Among them, the electrode 22 is mainly a combination of silver paste or copper foil and silver paste, which realizes the connection of the sub-heat-conducting layer 21 and the overcurrent. That is, a current loop is formed between the positive and negative terminals of the external power supply and the multiple electrodes 22. When one end of the multiple electrodes 22 is connected to the positive terminal of the external power supply and the other end is connected to the negative terminal of the external power supply, the current of the external power supply can flow from the positive terminal through one end of each electrode 22 to the other end of the corresponding electrode 22, and from the other end of the electrode 22 to the negative terminal of the external power supply. That is, each electrode 22 can transfer the overcurrent to the heat-conducting layer 2. The multiple electrodes 22 arranged at intervals can transfer current to different positions of the two sub-heat-conducting layers 21. That is, multiple electrodes 22 are provided between the two sub-heat-conducting layers. The multiple electrodes 22 supply power to the sub-heat-conducting layer 21. This is usually used in scenarios that require precise control of the heating area. Moreover, when each electrode 22 is independently connected to the positive and negative terminals of the external power supply, independent control of each electrode 22 can be realized, thereby realizing the zoned heating of the sub-heat-conducting layer 21.
[0044] In some embodiments, the sub-thermal conductive layer 21 is a PTC material. PTC material refers to a material whose resistivity increases with increasing temperature, and it is mainly an organic material. Such materials are composed of a polymer matrix and a conductive material. The polymer matrix can be polyethylene, polypropylene, etc., and the conductive material can be carbon black, carbon nanotubes, metal particles, etc. Because graphene has a thermal conductivity of 100-10000 W / m^2.K, the entire insulating film can achieve 100% high thermal conductivity. When the temperature is low, the resistance value of the PTC material remains basically unchanged within a certain range. However, when the temperature reaches a certain specific value, called the Curie temperature, its resistance value will suddenly increase with the increase of temperature. Usually, within a very small temperature range, such as a few degrees Celsius to a dozen degrees Celsius, the resistance value can rapidly increase to 10^3-10^5 times the original value. PTC can conduct heat quickly and the dry-burning temperature is controllable. That is, when it is necessary to heat the cell 6, it can be heated within the Curie temperature range. When it exceeds the Curie temperature, the resistance increases and the current of electrode 22 becomes too small. At this time, the resistance of the PTC layer increases and the temperature will not continue to rise, thus achieving the effect of controllable heating temperature of cell 6.
[0045] PTC materials may include conductive materials such as carbon nanotubes, which have excellent electrical conductivity and high thermal conductivity, further enhancing the thermal conductivity of the insulating film 100, enabling rapid transfer of heat from the battery or the heating element, thereby achieving the performance of a single battery that can both insulate and control the temperature.
[0046] In some embodiments, the insulating layer 1 may be selectively made of PET material according to different Curie temperatures of the sub-thermal conductive layer 21.
[0047] In practice, the sub-thermal conductive layer 21 is made of PTC material, and the Curie temperature of the PTC material can be adjusted by adding metal or non-metal oxide dopants to the polymer PTC material.
[0048] Therefore, for the insulating film 100 of the integrated sub-heat-conducting layer 21, the material of the insulating layer 1 can be flexibly selected. For example, for the sub-heat-conducting layer 21 with a Curie temperature of 85°C, the continuous temperature resistance of the insulating layer 1 can be controlled within the range of 85-100°C while meeting the insulation performance requirements; when the Curie temperature of the sub-heat-conducting layer 21 is controlled at 65°C, the continuous temperature resistance of the insulating layer 1 can be controlled within the range of 65-85°C while meeting the insulation performance requirements. This method allows for the selection of different materials for the insulating layer 1 based on the different Curie temperatures of the sub-heat-conducting layer 21, further reducing the temperature resistance standard of the insulating layer 1 material and thus reducing material costs.
[0049] For example, the insulating layer 1 can be made of non-metallic materials such as PET, PI, and PP. PET has the highest temperature resistance. For the sub-thermal conductive layer 21 with a Curie temperature point controlled at 85°C, PET material can be selected as the insulating layer 1 to improve the temperature resistance of the insulating layer 1. When the Curie temperature point is controlled at 65°C, other materials for the insulating layer 1 can be selected. This allows for the selection of a suitable insulating layer 1 with a lower cost for different Curie temperatures, thereby saving the cost of manufacturing the insulating film 100.
[0050] In some embodiments, at least one insulating layer 1 has a tearable centrifugal layer 5 attached to its outer side. (Refer to...) Figure 1 As shown, in practice, the centrifugal layer 5 is bonded to one side of the insulation layer 1 by double-sided adhesive 4. The centrifugal layer 5 is also known as centrifugal paper. The centrifugal paper is a protective transfer layer for the insulation film 100, enabling the independent placement and differentiation of each insulation film 100. When in use, the centrifugal paper needs to be removed, and the insulation film 100 can be bonded to the surface of the cell 6 by double-sided adhesive 4. The bonding is convenient and can better protect the insulation film 100. After tearing off the centrifugal layer 5, the insulation film 100 can be applied to multiple sides of a single cell 6 based on the characteristics of the cell 6, thereby achieving the function of multi-sided heating and multi-sided insulation of a single cell 6.
[0051] Of course, in actual design, centrifugal layers 5 can be set on the opposite side of the two insulation layers 1 to protect the insulation layers 1. When in use, the centrifugal layer 5 on one side can be torn open to connect with the battery cell 6. The other layer of insulation layer 1 exposed on the outside can also have the centrifugal layer 5 torn open, so that it can insulate, heat and conduct heat to the battery cell 6.
[0052] In some embodiments, the thermally conductive layer 2 is applied to the insulating layer 1 by coating. That is, the thermally conductive layer 2 can be directly bonded to the insulating layer 1 using adhesive 3, or it can be applied to the insulating film 100 by coating. The coating method allows control over the thickness, coating area, and uniformity of the thermally conductive layer 2. Alternatively, the thermally conductive layer 2 can be applied to the insulating layer 1 by printing, offering high flexibility and allowing for zoned design of heating power at the ends and middle of the battery cell 6. The PTC material is manufactured using a mixing process. Based on thermal characteristics, the thickness, width, and length of the PTC can be varied to meet different resistance and heating power requirements in different areas, thereby achieving uniform temperature. Furthermore, considering the characteristics of the PTC material, the maximum temperature of the insulating film 100 can be controlled to not exceed 100°C, achieving temperature controllability and reliable lifespan for the insulating film 100.
[0053] This utility model embodiment also discloses a battery, including a battery cell 6 and the above-mentioned insulating film 100, the insulating film 100 covering the outside of the battery cell 6.
[0054] In other words, the thermally conductive layer 2 of the battery's insulating film 100 can heat the battery cell 6 and better transfer the heat of the battery cell 6, thereby enhancing the battery's safety and increasing its lifespan.
[0055] This utility model embodiment also discloses a battery assembly 1000, which includes multiple batteries as described above, and the multiple insulating films 100 of the multiple batteries are connected in series through an electric heating part.
[0056] Reference Figure 4 and Figure 6 As shown, Figure 4 This is a schematic diagram showing the insulating film 100 located at the bottom of the battery cell 6. The specific design can be adjusted according to actual conditions. Figure 5 In this battery, an insulating film 100 can be provided around each cell 6 to form a battery. The insulating film 100 not only has the function of insulation, but the insulating films 100 between two adjacent batteries can also be electrically connected through the electric heating part, thereby realizing the series connection of multiple insulating films 100 of multiple batteries.
[0057] The insulating film 100 of a single battery cell 6 can heat that single cell 6. Multiple insulating films 100 of multiple cells 6 can be connected to achieve simultaneous heating of multiple cells 6. Considering the spacing between cells 6 is 0-5mm, conventional insulating films 100 cannot achieve wiring harness connections, or additional heating structures and heating circuits are required, which would occupy space in the battery assembly 1000, such as encroaching on space between adjacent cells. However, for insulating films 100 with integrated heating functions, the two cells can be connected by connecting the electrodes 22 of the insulating films 100 of two cells in series; and the upper... The insulating film 100 of one battery is connected to the insulating film 100 of the next battery through the lead-out end of the electrode 22. The lead-out length of the electrode 22 is 2-10mm. If the width of the heat-conducting layer 2 along the arrangement direction of multiple cells 6 is greater than or equal to the width of each cell 6, the connection between the two batteries is realized. Since the heat-conducting layer 2 is an organic non-metallic material and the insulating layer 1 is a material such as PI or PET, it has good flexibility. Therefore, the insulating layer 1 and the heat-conducting layer 2 can be bent into different shapes to achieve connection, that is, to achieve flexible connection, which can absorb the gap between batteries and not occupy the space between batteries.
[0058] In some embodiments, each cell 6 is covered with an insulating film 100 along a first direction and another insulating film 100 along a second direction, and the electric heating portions between the insulating films 100 of adjacent cells are connected in series.
[0059] Reference Figure 5 As shown, the first direction can be the direction in which the battery cell 6 is wound around once along its length, and the second direction can be along... Figure 5 The width direction is used to wrap around the entire cell, for example, after wrapping the insulating film 100 along the length direction of each cell 6, another layer of insulating film 100 is selected and wrapped along the width direction of each cell 6, and... Figure 5 The electrodes 22 of the insulating film 100 surrounding the width of the cell 6 can be located at both ends of each cell 6; and each cell 6 has a positive lead-out terminal 221 at one end and a negative lead-out terminal 222 at the other end of the insulating film 100 along the length of the cell 6. The positive lead-out terminals 221 of the insulating films 100 of two adjacent cells are connected, and the negative lead-out terminals 222 of the insulating films 100 of two adjacent cells are connected, thereby realizing the series connection between the heat-conducting layers 2 of the insulating films 100 of two adjacent cells. Thus, after the electrodes 22 are energized, the current can flow along the heat-conducting layer 2 of one cell to the heat-conducting layer 2 of another cell. That is, when the battery assembly 1000 is heated, multiple cells 6 can be heated. When heating is not required, the heat transfer of the battery assembly 1000 is carried out through the heat-conducting layer 2 of the insulating film 100 of each cell.
[0060] In other words, Figure 5The design of the heat-conducting layer 2 of the insulating film 100 and the electrode 22 allows for zoned design of the heating power at the ends and middle of the battery cell 6 according to actual conditions, thereby achieving differences in heating power density at different locations. For example, the power density of the heat-conducting layer 2 located in the middle of the battery cell 6 may be relatively small. By reducing the density of the electrode 22 in the middle, the power density of the electrode 22 at the ends of the battery cell 6 may be increased, thus achieving the design of heating power at different locations of the battery cell 6.
[0061] In some embodiments, the same side of the plurality of batteries includes an electric heating portion extending in the same direction, and the extending direction of the electric heating portion is consistent with the arrangement direction of the plurality of batteries, and adjacent batteries are electrically connected through adjacent electric heating portions.
[0062] Reference Figure 6 As shown, multiple battery cells 6 are connected along... Figure 6 Arranged in a left-right direction, each battery cell is covered with an insulating film 100 to form a battery, that is, multiple batteries are arranged along... Figure 6 The cells are arranged in a left-right direction. A magnified view of the insulating film (100mm) on the side of each cell is shown below. Figure 7 As shown, Figure 7 The diagram illustrates the connection of the electrode 22 to the sub-heat-conducting layers 21 on both sides. Each sub-heat-conducting layer 21 has an insulating layer 1 connected to the side opposite to each other. That is, the electrodes 22 between two adjacent batteries are electrically connected along the arrangement direction of multiple batteries, which makes it easier to connect adjacent batteries. After the electrode 22 is electrically connected to an external power source, the current can flow from one battery to another to heat the battery assembly 1000, or make the battery assembly 1000 conduct heat to the outside.
[0063] In addition, the overall thickness of the insulating film 100 can be controlled within 0.1-0.3mm, achieving multiple functions such as insulation, heating, and temperature equalization. The thickness of each sub-thermal conductive layer 21 is 5-30um, enabling an ultra-thin design. This ensures the insulation and heating performance of the insulating film 100 while reducing its thickness, thus increasing the energy density of the battery cell 6. However, increasing the thickness of the insulating film 100 would lengthen the diffusion path of ions in the active material, increasing the battery's internal resistance. Increased internal resistance leads to more heat generation during charging and discharging, which not only reduces energy conversion efficiency but may also negatively impact battery life. Therefore, reducing the thickness of the insulating film 100 can mitigate the problems of low energy conversion efficiency and shortened lifespan caused by increased battery internal resistance.
[0064] Moreover, the insulating film 100 of this utility model embodiment can be heated at any time, and the heating and dry burning are controllable. It has high heating efficiency, can realize different heating structure forms, and the power density can be flexibly adjusted based on the battery cell, reducing the contradiction between rapid heating and rapid heat conduction. By adding an additional sub-heat conducting layer 21, rapid heat conduction under fast charging and cooling is achieved, reducing the problem of low thermal conductivity of the insulating layer 1.
[0065] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0066] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.
Claims
1. An insulating film, characterized by, The application relates to an insulation film for a battery, which comprises: at least two insulation layers; a heat-conducting layer arranged between the two insulation layers, the heat-conducting layer being provided with an electric heating part adapted to be connected to an external power source; the heat-conducting layer comprises two sub-heat-conducting layers, the electric heating part is arranged between the two sub-heat-conducting layers, and the two sub-heat-conducting layers are respectively connected to one of the insulation layers at the sides away from each other; the two sub-heat-conducting layers are symmetrical about the electric heating part; the electric heating part comprises a plurality of electrodes arranged at intervals, one end of the plurality of electrodes is connected to the positive pole of the external power source, and the other end is connected to the negative pole of the external power source, each of the electrodes can be independently connected to the external power source, and each of the electrodes is independently controlled to realize partition heating of the sub-heat-conducting layers.
2. The insulating film according to claim 1, characterized by The sub-heat-conducting layer is made of PTC material.
3. The insulating film according to claim 2, characterized by The insulation layer can be made of PET material according to the different Curie temperatures of the sub-heat-conducting layers.
4. The insulating film according to claim 1, characterized by The outer side of at least one of the insulation layers is connected to a tearable centrifugal layer.
5. The insulating film according to claim 1, characterized by The heat-conducting layer is arranged on the insulation layer by coating.
6. A battery, characterized by The application also relates to a battery cell and an insulation film for the battery cell, the insulation film is arranged on the outer side of the battery cell.
7. A battery assembly characterized by, The application also relates to a plurality of battery cells, the electric heating parts between the insulation films of the plurality of battery cells are connected in series.
8. The battery assembly of claim 7, wherein, Each of the battery cells is wrapped with one of the insulation films in a first direction and wrapped with another of the insulation films in a second direction, and the electric heating parts between the insulation films of adjacent battery cells are connected in series.
9. The battery assembly of claim 7, wherein, The same side of the plurality of battery cells comprises the electric heating parts with the same extending direction, and the extending direction of the electric heating parts is consistent with the arrangement direction of the plurality of battery cells, and the adjacent battery cells are electrically connected through the adjacent electric heating parts.