Heating film

Abstract

The utility model discloses a heating film. The heating film comprises a film sheet and a heating wire, the diaphragm is composed of a plurality of planar diaphragms, the planar diaphragms are attached to the surfaces of the battery cells, and the planar diaphragms are matched with the battery cells in size and number; a connecting diaphragm is arranged between every two adjacent plane diaphragms, each connecting diaphragm is provided with an arch-shaped structure, and the arch-shaped structures are positioned in gaps between every two adjacent battery cells; the heating wire is arranged on the diaphragm in a bending manner, and the end part of the heating wire is provided with a wire outlet end. According to the utility model, the diaphragm is divided into a plurality of units, and the deformation characteristic of the arched structure for connecting the diaphragm is utilized, so that the problem that the heating diaphragm is separated from the battery cells due to expansion deformation of different degrees on the surface of each battery cell after the use attenuation of the battery is effectively solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of new energy, and in particular relates to a heating film. Background Art

[0002] Lithium batteries store or release electricity through chemical reactions, and temperature has a significant impact on chemical reactions, especially when the battery is in a low temperature environment below 0°C, the battery is not allowed to be charged. In order to meet the need for a reliable and stable heating module when using the battery at low temperatures, heating film is widely used in battery packs because of its high heating efficiency and low cost.

[0003] Most of the heating films currently used are flat heating films, that is, the main body of the film is fixed to the two sides or bottom of the battery module with double-sided tape. The flat heating film does not take into account the expansion characteristics of the battery after the battery life decays. This is mainly because the surface of each battery cell will undergo different degrees of expansion and deformation after the battery decays. This deformation will cause the double-sided tape attached to the heating film to debond, causing the heating film to separate from the battery cell, or in severe cases, the heating film may be pulled apart, affecting the normal use of the heating film and posing a huge safety hazard. Utility Model Content

[0004] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a heating film to solve the problems in the above-mentioned background technology.

[0005] The utility model adopts the following technical solution to solve the technical problem: a heating film is provided, comprising a diaphragm and a heating wire; the diaphragm is composed of a plurality of planar diaphragms, the planar diaphragms are attached to the surface of a battery cell, and the planar diaphragms are adapted to the size and quantity of the battery cell; a connecting diaphragm is provided between adjacent planar diaphragms, the connecting diaphragm has an arched structure, and the arched structure is located in the gap between adjacent battery cells; the heating wire is arranged on the diaphragm in a curved manner, and an outlet terminal is provided at the end of the heating wire.

[0006] In the utility model, the heating wire is packaged between two layers of diaphragms.

[0007] In the utility model, the heating wire is coiled on the diaphragm in a comb-teeth shape.

[0008] In the present invention, the width of the heating wire on the plane membrane is smaller than the width of the heating wire on the connecting membrane.

[0009] In the utility model, the heating wire is arranged on the planar diaphragm along the length direction of the planar diaphragm.

[0010] In the utility model, an insulating layer is provided on the surface of the outlet terminal, and the resistance of the outlet terminal is smaller than the resistance of the heating wire in the diaphragm.

[0011] In the utility model, the flat film is attached to the side surface of the battery core through an adhesive layer.

[0012] In the utility model, the center distance between two adjacent connecting diaphragm arch structures is equal to the thickness of the battery core.

[0013] In the present invention, the concave direction of the arch structure is toward the gap.

[0014] In the utility model, the diaphragm is made of PET material.

[0015] Compared with the background technology, this technical solution has the following advantages:

[0016] The diaphragm structure of this solution is different from the traditional flat type. Instead, the diaphragm is unitized into several flat diaphragms and arched connecting diaphragms. Each flat diaphragm is independently attached to the side of a single battery cell. When the surface of the battery cell expands and deforms to varying degrees, the arched structure deforms accordingly. Since the connecting diaphragm is not in contact with the surface of the battery cell, its deformation will not affect the flat diaphragm of the heating film and will not generate mutual pulling forces. This can ensure that the flat diaphragm can always be fixed intact on a single battery cell and will not be separated from or pulled apart from the battery cell. In addition, the heating wire arrangement method of this solution has a certain amount of expansion and contraction to adapt to the expansion and deformation of the battery cell. Different widths are set according to different positions, or the heating wire at the connecting diaphragm position is made of a material with a relatively small resistivity. This can also ensure that the heating film is heated evenly during the overall heating process to avoid excessive local dry burning temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 This is a diagram of the heating film structure of an embodiment;

[0019] Figure 2 This is a structural diagram of a single-layer diaphragm and an outlet terminal of a heating film in an embodiment;

[0020] Figure 3 for Figure 2 A front view of

[0021] Figure 4 The structure diagram of the battery cell;

[0022] Figure 5 Schematic diagram of the heating wire winding method.

[0023] Among them, 1-diaphragm, 11-flat diaphragm, 12-connecting diaphragm, 2-heating wire, 3-outlet terminal, 4-double-sided adhesive layer, 5-battery core. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0026] Example

[0027] A heating film includes a diaphragm 1 and a heating wire 2. In this embodiment, the diaphragm 1 is made of PI material, so that the diaphragm 1 has excellent physical and mechanical properties and electrical insulation, and maintains good electrical properties, fatigue resistance, friction resistance, and dimensional stability at high temperatures. The heating wire 2 is encapsulated between two layers of diaphragms 1, and the projections of the two layers of diaphragms 1 overlap, which not only protects the heating wire 2, but also ensures the consistency of the ductility of the structure.

[0028] The diaphragm is composed of a plurality of planar diaphragms 11, which are attached to the side of the battery cell 5 through a double-sided adhesive layer 4, and the thickness and number of the planar diaphragms 11 are adapted to the side of the battery cell 5; a connecting diaphragm 12 is provided between adjacent planar diaphragms 11, and the connecting diaphragm 12 has an arched structure, and the arched structure is located in the gap between adjacent battery cells 5; Figure 2 and 3 The center distance L1 between two adjacent arch structures of the connecting diaphragms 12 is equal to the thickness L2 of the battery cell 5, and the concave direction of the arch structure is toward the gap.

[0029] The end of the heating wire 2 is provided with an outlet terminal 3, and the surface of the outlet terminal 3 is provided with an insulating layer. The resistance of the outlet terminal 3 is smaller than the resistance of the heating wire 2 in the membrane, which can minimize the heat generated by the outlet terminal 3 of the heating film.

[0030] The initial state of the heating wire 2 includes a wavy shape, a W shape, an N shape or other shapes, which satisfies that the heating wire 2 has a certain amount of flexible expansion, can adapt to the expansion and deformation of the battery cell 5, and ensure the normal use of the heating film. The heating wire 2 is formed in an integrated manner, or is formed by rolling a whole piece of copper foil, aluminum foil or stainless steel on a round roller, or is directly die-cut into the required shape using a whole flat piece of copper foil, aluminum foil or stainless steel. In the present embodiment, the heating wire 2 is coiled on the diaphragm in a comb-tooth shape, specifically: the heating wire 2 is first arranged on the flat diaphragm 11 along the length direction of the flat diaphragm 11 and then coiled in a circuitous manner, and after bending at the end of the flat diaphragm 11, it crosses the connecting diaphragm 12 and is arranged in a circuitous manner from the end of the next flat diaphragm 11 to the head end. Figure 5 The width L3 of the heating wire 2 on the plane diaphragm 11 is smaller than the width L4 on the connecting diaphragm 12, so that the resistivity of the heating wire 2 at the connecting diaphragm 12 is smaller than that at the plane diaphragm 11, which can ensure that the heating film is heated evenly during the overall heating process and avoid excessive dry burning temperature in the local area.

[0031] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heating film, characterized in that: It comprises a diaphragm and a heating wire; the diaphragm is composed of a plurality of planar diaphragms, the planar diaphragms are attached to the surface of the battery cell, and the planar diaphragms are adapted to the size and quantity of the battery cell; a connecting diaphragm is arranged between adjacent planar diaphragms, the connecting diaphragm has an arch structure, and the arch structure is located in the gap between adjacent battery cells; the heating wire is arranged on the diaphragm in a curved manner, and an outlet terminal is arranged at the end of the heating wire; the heating wire is coiled on the diaphragm in a comb-teeth shape.

2. A heating film according to claim 1, characterized in that: The heating wire is packaged between two layers of diaphragms.

3. A heating film according to claim 1, characterized in that: The width of the heating wire on the planar membrane is smaller than the width of the heating wire on the connecting membrane.

4. A heating film according to claim 1, characterized in that: The heating wires are arranged on the planar diaphragm along the length direction of the planar diaphragm.

5. The heating film according to claim 1, characterized in that: An insulating layer is provided on the surface of the outlet terminal, and the resistance of the outlet terminal is smaller than the resistance of the heating wire in the diaphragm.

6. A heating film according to claim 1, characterized in that: The flat film is attached to the side of the battery core through an adhesive layer.

7. A heating film according to claim 1, characterized in that: The center distance between two adjacent connecting diaphragm arch structures is equal to the thickness of the battery cell.

8. The heating film according to claim 1, characterized in that: The concave direction of the arch structure is toward the gap.

9. The heating film according to claim 1, characterized in that: The diaphragm is made of PI material.

Images