Heating film assembly and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a heating film assembly and a battery pack, the heating film assembly is used for heating a battery unit comprising a plurality of batteries arranged in sequence, and the heating film assembly comprises a film body, a heating wire and a memory alloy skeleton. The membrane body comprises two membrane sheets, and the two membrane sheets are attached to each other. And the heating wire is arranged between the two membranes. The memory alloy framework is fixedly arranged between the two membranes, the memory alloy framework is suitable for generating deformation under the condition of heating, and the deformation can enable the membrane body to tend to be attached to the battery unit. The memory alloy framework can be straightened again through high temperature generated by dry burning, so that the heating area separated from the battery is tightly attached to the side face of the battery under the action of pulling force, the effects of reducing the dry burning temperature and preventing dry burning are achieved, and dry burning caused by failure of an adhesive layer is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a heating film assembly and a battery pack. BACKGROUND

[0002] With the rapid development of electric vehicles and energy storage technologies, the stability and reliability of batteries as their core power source become particularly important. Especially in low temperature environments, the discharge performance of the battery will decrease significantly, which directly affects the cruising range of electric vehicles and the overall efficiency of energy storage systems. In order to overcome this problem, preheating technology is usually used to raise the battery to a reasonable operating temperature range to ensure its normal operation.

[0003] Among many thermal management solutions, heating films are widely used in battery packs including batteries due to their simple structure, uniform heating and easy installation. The heating film is usually composed of an insulating film and a heating wire packaged inside the insulating film. In actual application, the heating film is tightly attached to the side of the battery cell through a glue layer, and the heat generated by the heating wire is used to heat the battery inside the battery cell through heat conduction, thereby achieving the effect of rapid heating.

[0004] In related technologies, when the bonding performance of the glue layer decreases over time or with changes in the environment, the heating film and the battery may separate. This separation not only reduces the heat conduction efficiency, but also can cause the heating film to appear "dry burning" in local areas, that is, the heating wire continues to work but the heat cannot be effectively transferred to the battery, thereby causing safety hazards such as overheating, short circuit, and even fire. UTILITY MODEL CONTENT

[0005] Therefore, the present application provides a heating film assembly and a battery pack to solve the problem of dry burning caused by the failure of the glue layer.

[0006] In a first aspect, the present application provides a heating film assembly for heating a battery cell comprising a plurality of batteries arranged in sequence, comprising a film body, a heating wire and a memory alloy framework. The film body comprises two film sheets, and the two film sheets are attached. The heating wire is fixedly arranged between the two film sheets. The memory alloy framework is arranged between the two film sheets, and the memory alloy framework is adapted to deform under the action of heat, and the deformation can cause the film body to tend to attach to the battery cell.

[0007] Beneficial effects: the heating film assembly is provided with a memory alloy framework in the film body, when the heating film is separated from the battery, the high temperature generated by dry burning can make the memory alloy framework deform to straighten the film body, and then the film body separated from the battery is attached to the side of the battery under the action of the tension, so that the dry burning temperature is reduced and the dry burning is prevented. Compared with the way of adding a temperature sensor on the heating film to monitor the temperature of the heating film in real time, the heating film assembly in the application has simple structure, lower cost and more stable dry burning prevention effect.

[0008] In an alternative embodiment, the memory alloy framework comprises at least one first memory alloy, and / or a plurality of second memory alloys.

[0009] The extension direction of the first memory alloy is consistent with the length direction of the film body. The plurality of second memory alloys are arranged at intervals along the length direction of the film body, and the extension direction of the second memory alloy is perpendicular to the length direction of the film body.

[0010] Beneficial effects: the first memory alloy can be arranged on the two long sides of the film body to limit the film body from the length direction, when the film body is separated from the battery, the high temperature generated by dry burning of the heating area can make the first memory alloy deform to straighten the film body along the length direction, and then the film body separated from the battery is attached to the side of the battery under the action of the tension. The plurality of second memory alloys arranged at intervals in the film body and extending along the width direction of the film body can limit the film body from the width direction, when the film body is separated from the battery, the high temperature generated by dry burning of the heating area can make the second memory alloy deform to straighten the film body along the width direction, and then the film body separated from the battery is attached to the side of the battery under the action of the tension.

[0011] In an alternative embodiment, the film body is provided with two groups of second memory alloys, and the two groups of second memory alloys are arranged at the two ends of the film body along the length direction thereof, and each group of second memory alloys comprises at least one second memory alloy.

[0012] Beneficial effects: at least one second memory alloy is arranged on the two short sides of the film body along the length direction thereof, which can limit the film body from the width direction.

[0013] In an alternative embodiment, the film body is provided with two groups of first memory alloys, and the two groups of first memory alloys are arranged at the two ends of the film body along the width direction thereof, and each group of first memory alloys comprises at least one first memory alloy.

[0014] Beneficial effect: At least one first memory alloy is arranged on each of the two long edges of the film body along the width direction of the film body, which can limit the film body from the length direction.

[0015] In an alternative embodiment, expansion holes are arranged on the film body along the length direction of the film body, and the extension direction of the expansion holes is perpendicular to the length direction of the film body. Heating zones are formed between adjacent two expansion holes and between the expansion hole and the side edge of the film body adjacent to the expansion hole.

[0016] Beneficial effect: The expansion force generated by the battery charging and discharging under heat can be absorbed through the expansion hole.

[0017] Beneficial effect: The first memory alloy arranged at each end along the width direction of the film body can limit the film body from the length direction, and the first memory alloy arranged on both sides of the heating zone can avoid mutual interference between the first memory alloy and the heating zone.

[0018] In an alternative embodiment, the second memory alloy is arranged between the heating zone and the adjacent expansion hole, and / or between the heating zone and the side edge of the film body adjacent to the heating zone.

[0019] Beneficial effect: The second memory alloy arranged on both sides of each heating zone can limit both ends of each heating zone, which can strengthen the limiting effect, and the second memory alloy arranged on both sides of the heating zone can avoid mutual interference between the second memory alloy and the heating zone.

[0020] In an alternative embodiment, the first memory alloy and the second memory alloy are arranged in a long strip-shaped, wire-shaped or rod-shaped structure.

[0021] Beneficial effect: The first memory alloy and the second memory alloy arranged in a long strip-shaped, wire-shaped or rod-shaped structure can have a lower temperature required for deformation, which can improve the limiting protection effect and avoid high-temperature dry burning.

[0022] In an alternative embodiment, it further includes an outlet terminal, a wire, a male terminal and a female terminal.

[0023] Two wire outlet ends are arranged at the two ends of the film body along the length direction of the film body. Two wires are arranged and electrically connected with the heating wires respectively, and the two wires are fixed to the two wire outlet ends respectively.

[0024] Beneficial effects: the wire outlet end can fix the wire on the heating film assembly by welding. The male terminal and the female terminal are used as the power input joint of the heating film assembly to supply power to the heating film assembly, and the connection with the power supply is convenient, simple and reliable.

[0025] In a second aspect, the application further provides a battery pack comprising a battery cell and a heating film assembly.

[0026] The battery cell comprises a plurality of batteries arranged in sequence, and a glue layer is arranged between the battery cell and the heating film assembly, and the glue layer is used for bonding the battery cell and the heating film assembly.

[0027] Beneficial effects: because the battery pack comprises the heating film assembly, it has the same effects as the heating film assembly, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the specific embodiments of the application or the technical solutions in the prior art, the drawings needed in the description of the specific embodiments or the prior art will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0029] Fig. 1 The structure diagram of the first memory alloy arranged separately in the embodiment of the application;

[0030] Fig. 2 The structure diagram of the second memory alloy arranged separately in the embodiment of the application;

[0031] Fig. 3 The structure diagram of the first memory alloy and the second memory alloy arranged simultaneously in the embodiment of the application.

[0032] Explanation of reference signs:

[0033] 1, film body; 2, first memory alloy; 3, second memory alloy; 4, expansion hole; 5, wire outlet end; 6, wire; 7, male terminal; 8, female terminal. DETAILED DESCRIPTION

[0034] In order to make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0035] The embodiments of the present application are described below with reference to the drawings. Figs. 1 to 3

[0036] According to the embodiments of the present application, in one aspect, a heating film assembly for heating a battery unit including a plurality of batteries arranged in sequence is provided, including a film body 1, a heating wire, and a memory alloy framework. The film body 1 includes two film sheets, and the two film sheets are attached to each other. The heating wire is fixedly arranged between the two film sheets. The memory alloy framework is arranged between the two film sheets, and the memory alloy framework is adapted to deform under the condition of being heated. The deformation of the memory alloy framework can make the film body 1 tend to attach to the battery unit.

[0037] In the present embodiment, the heating film assembly is provided with the memory alloy framework in the film body 1. When the heating film and the battery are separated, the high temperature generated by dry burning can make the memory alloy framework deform to straighten the film body 1, so that the film body 1 separated from the battery is attached to the side surface of the battery under the action of the pulling force, which can reduce the dry burning temperature and prevent dry burning. Compared with the way of adding a temperature sensor on the heating film to monitor the temperature of the heating film in real time, the heating film assembly in the present application has a simple structure, a lower cost, and a more stable dry burning prevention effect.

[0038] In some embodiments, the memory alloy framework includes at least one first memory alloy 2. The extension direction of the first memory alloy 2 is consistent with the length direction of the film body 1.

[0039] Alternatively, the memory alloy framework can be provided with only the first memory alloy 2, and the first memory alloy 2 is provided with at least one. The extension direction of the first memory alloy 2 is consistent with the length direction of the film body 1.

[0040] Referring to Fig. 1 Alternatively, the memory alloy framework can be provided with only the first memory alloy 2, and the first memory alloy 2 is provided with at least one. The extension direction of the first memory alloy 2 is consistent with the length direction of the film body 1.

[0041] Referring to Fig. 2 ​Optionally, the memory alloy skeleton can be provided as the second memory alloy 3 only, and the second memory alloy 3 is provided in multiple, the multiple second memory alloys 3 are provided at intervals along the length direction of the film body 1, and the extension direction of the second memory alloy 3 is perpendicular to the length direction of the film body 1.

[0042] Referring to Fig. 3 Optionally, the memory alloy skeleton can include the multiple first memory alloys 2 and the multiple second memory alloys 3, that is, the first memory alloy 2 and the second memory alloy 3 can be provided in the film body 1 at the same time.

[0043] Optionally, two groups of the second memory alloys 3 are provided in the film body 1, and the two groups of the second memory alloys 3 are respectively provided at two ends of the film body 1 along the length direction thereof, and each group of the second memory alloys 3 includes at least one second memory alloy 3. At least one second memory alloy 3 is provided at each of the two short sides of the film body 1 along the length direction thereof, which can limit the film body 1 from the width direction.

[0044] Optionally, two groups of the first memory alloys 2 are provided in the film body 1, and the two groups of the first memory alloys 2 are respectively provided at two ends of the film body 1 along the width direction thereof, and each group of the first memory alloys 2 includes at least one first memory alloy 2. At least one first memory alloy 2 is provided at each of the two long sides of the film body 1 along the width direction thereof, which can limit the film body 1 from the length direction.

[0045] Optionally, the expansion holes 4 are provided at intervals along the length direction of the film body 1 on the film body 1, and the extension direction of the expansion hole 4 is perpendicular to the length direction of the film body 1, and a heating zone is formed between adjacent two expansion holes 4 and between the expansion hole 4 and the side edge of the film body 1 adjacent to the expansion hole 4. The expansion force generated by the battery charging and discharging under heating can be absorbed through the expansion hole.

[0046] Optionally, two groups of the first memory alloys 2 are provided at intervals along the width direction of the film body 1, each group of the first memory alloys 2 includes at least one first memory alloy 2, and the two groups of the first memory alloys 2 are respectively provided on two sides of the heating zone. The first memory alloy 2 provided at each of the two ends along the width direction of the film body 1 can limit the film body 1 from the length direction, and the first memory alloy 2 provided on the two sides of the heating zone can avoid the mutual interference between the first memory alloy 2 and the heating zone.

[0047] Optionally, the second memory alloy 3 is provided between the heating zone and the adjacent expansion hole 4, and / or between the heating zone and the side edge of the film body 1 adjacent to the heating zone. The second memory alloy 3 provided on the two sides of each heating zone can limit each heating zone from both ends, strengthen the limiting effect, and the second memory alloy 3 provided on the two sides of the heating zone can avoid the mutual interference between the second memory alloy 3 and the heating zone.

[0048] Optionally, the memory alloy framework can comprise both the first memory alloy 2 and the second memory alloy 3, or only one of them. The first memory alloy 2 and the number and manner of its arrangement, and the second memory alloy 3 and the number and manner of its arrangement can be combined arbitrarily.

[0049] In this embodiment, the first memory alloy 2 can be arranged on both long edges of the film body 1 to limit the film body 1 in the length direction. When the film body 1 is separated from the battery, the high temperature generated by dry burning of the heating zone can cause the first memory alloy 2 to deform, so as to straighten the film body 1 in the length direction again, and then the film body 1 separated from the battery is tightly attached to the side of the battery under the action of the tension. The second memory alloy 3 arranged in the middle of the film body 1 and extending in the width direction of the film body 1 can limit the film body 1 in the width direction. When the film body 1 is separated from the battery, the high temperature generated by dry burning of the heating zone can cause the second memory alloy 3 to deform, so as to straighten the film body in the width direction again, and then the film body 1 separated from the battery is tightly attached to the side of the battery under the action of the tension.

[0050] In some embodiments, the first memory alloy 2 and the second memory alloy 3 are arranged in a long strip-shaped wire structure or a rod structure or a sheet structure.

[0051] In this embodiment, the first memory alloy 2 and the second memory alloy 3 are arranged in a long strip-shaped wire structure or a rod structure or a sheet structure, which can make the first memory alloy 2 and the second memory alloy 3 have a lower temperature required for deformation, improve the limiting protection effect, and avoid high-temperature dry burning.

[0052] Optionally, the memory alloy framework can also be arranged in a ring structure, and the heating zone can be located in the area surrounded by the memory alloy framework.

[0053] Optionally, the memory alloy framework can also be arranged in a mesh structure, and the heating zone can not overlap with the memory alloy framework.

[0054] In some embodiments, the film body 1 is arranged as a polyimide film, and the memory alloy framework is arranged as a nickel-titanium alloy framework.

[0055] Optionally, the material of the heating wire can be copper or its alloy or other materials according to the design power. The heating wire is embedded in the middle of the two layers of polyimide film through hot pressing or other processes, and the polyimide film can play an insulating protection role.

[0056] In the embodiment, the nickel-titanium alloy framework can automatically restore its shape in the parent phase at a certain temperature, thereby ensuring that the heating film assembly can be attached to the battery again when dry burning occurs. The polyimide film has excellent high temperature resistance, radiation resistance, chemical corrosion resistance and electrical insulation performance.

[0057] In some embodiments, the outlet end, the lead wire 6, the male terminal 7 and the female terminal 8 are further included.

[0058] The two outlet ends 5 are arranged at the two ends of the film body 1 along the length direction of the film body 1. The two lead wires 6 are respectively electrically connected to the heating wires, and the two lead wires 6 are fixed to the two outlet ends 5. The male terminal 7 and the female terminal 8 are respectively connected to the ends of the two lead wires 6 away from the outlet ends 5.

[0059] In the embodiment, the outlet ends 5 can fix the lead wires 6 on the heating film assembly by welding. The male terminal 7 and the female terminal 8 are used as the power input connector of the heating film assembly to supply power to the heating film assembly. The connection with the power supply is convenient, simple and reliable.

[0060] According to the embodiments of the present application, on the other hand, a battery pack is also provided, which includes a battery unit and a heating film assembly.

[0061] The battery unit includes a plurality of batteries arranged in sequence. A glue layer is arranged between the battery unit and the heating film assembly, and is used to bond the battery and the heating film assembly.

[0062] In the embodiment, the battery pack includes the heating film assembly, which has the same effect as the heating film assembly, and will not be described here.

[0063] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.

Claims

1. A heating film assembly, characterized in that, A battery cell comprising multiple batteries arranged in sequence is used for heating, including: The membrane body (1) includes two membrane sheets, which are attached together; A heating wire is disposed between the two diaphragms; A shape memory alloy skeleton is fixedly disposed between the two membranes. The shape memory alloy skeleton is adapted to deform under heat, and the deformation causes the membrane body (1) to tend to fit the battery cell.

2. The heating film assembly according to claim 1, characterized in that, The shape memory alloy skeleton includes: At least one first memory alloy (2), wherein the extension direction of the first memory alloy (2) is consistent with the length direction of the membrane body (1); And / or, a plurality of second memory alloys (3), the plurality of second memory alloys (3) being spaced apart along the length direction of the membrane body (1), and the extension direction of the second memory alloys (3) being perpendicular to the length direction of the membrane body (1).

3. The heating film assembly according to claim 2, characterized in that: The membrane body (1) is provided with two sets of the second memory alloy (3), and the two sets of the second memory alloy (3) are respectively disposed at both ends of the membrane body (1) along its length direction, and each set of the second memory alloy (3) includes at least one second memory alloy (3).

4. The heating film assembly according to claim 2, characterized in that: The membrane body (1) is provided with two sets of the first memory alloy (2), and the two sets of the first memory alloy (2) are respectively disposed at both ends of the membrane body (1) along its width direction, and each set of the first memory alloy (2) includes at least one first memory alloy (2).

5. The heating film assembly according to claim 2, characterized in that: The membrane body (1) is provided with expansion holes (4) spaced apart along the length direction of the membrane body (1), and the extension direction of the expansion holes (4) is perpendicular to the length direction of the membrane body (1). A heating zone is formed between two adjacent expansion holes (4) and between the expansion holes (4) and the side edge of the membrane body (1) adjacent to them.

6. The heating film assembly according to claim 5, characterized in that: Along the width direction of the membrane body (1), two sets of the first memory alloy (2) are spaced apart, each set of the first memory alloy (2) includes at least one first memory alloy (2), and the two sets of the first memory alloy (2) are respectively disposed on both sides of the heating zone.

7. The heating film assembly according to claim 5, characterized in that: The second shape memory alloy (3) is disposed between the heating zone and the adjacent expansion hole (4), and / or between the heating zone and the side edge of the adjacent membrane body (1).

8. The heating film assembly according to claim 2, characterized in that: Both the first shape memory alloy (2) and the second shape memory alloy (3) are configured as long strip-shaped filament structures, rod structures, or sheet structures.

9. The heating film assembly according to claim 1, characterized in that, Also includes: There are two outlet terminals (5), and the two outlet terminals (5) are arranged at both ends of the membrane body (1) along the length direction of the membrane body (1); Two wires (6) are provided, which are electrically connected to the heating wire respectively. The two wires (6) are fixed relative to the two outlet terminals (5); The male terminal (7) and the female terminal (8) are respectively connected to the ends of the two wires (6) away from the outlet terminal (5).

10. A battery pack, characterized in that, include: A battery cell, comprising multiple batteries arranged in sequence; According to any one of claims 1 to 9, an adhesive layer is provided between the battery cell and the heating film assembly, the adhesive layer being used to bond the battery cell and the heating film assembly.

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