Multi-surface heating film and battery cell

Abstract

The utility model relates to the technical field of lithium ion power battery thermal management, in particular to a multi-face heating film which comprises a heating film body, the heating film body comprises a middle heating film and side heating films connected to the two sides of the middle heating film respectively, and the middle heating film and the side heating films are rectangular. The middle heating film is provided with through holes for the positive and negative poles and the explosion-proof valve to pass through, wear-resistant PC sheets are adhered to the two ends of the side heating film along the long edge direction, gaps are arranged on the heating film at equal intervals, at least two positive and negative wiring terminals are arranged on the heating film, and the positive and negative wiring terminals are connected with the heating film body through a circuit. The battery cell comprises a battery cell body and further comprises the multi-surface heating film, the side heating film is adhered to the side surface of the battery cell body, the through hole of the middle heating film is sleeved on the positive and negative pole columns and the explosion-proof valve of the battery cell and is adhered to the upper part of the battery cell body, and the upper end and the lower end of the battery cell along the long edge direction are respectively provided with a circle of steel belt hooped on the outer side of the wear-resistant sheet. The device is mainly used for improving the uniform heating performance and the heat preservation performance of the battery cell.

Description

Technical Field

[0001] This utility model relates to the field of thermal management technology for lithium-ion power batteries, specifically to a multi-faceted heating film and a battery cell. Background Technology

[0002] Currently, lithium-ion batteries for new energy vehicles typically require heating in low-temperature environments to improve their charge-discharge performance and safety. Heating films are commonly used to heat the battery cells because they have rapid heating capabilities, achieving high heating rates with relatively low energy consumption. However, existing heating films are limited by the cell's structural design. The cell has steel strips binding its top and bottom ends along its length, and wear-resistant PC sheets are located where these strips bind. The heating film is obstructed by the steel strips and can only be placed in the area between the steel strips on both sides of the cell. The top of the cell has protruding positive and negative terminals and an explosion-proof valve. This results in a small heating area, limited heating zone, uneven heating, low efficiency, and insufficient heat retention. Consequently, lithium-ion batteries cannot achieve optimal charge-discharge performance in low-temperature environments, posing safety hazards.

[0003] Therefore, in view of the shortcomings of the existing technology, there is an urgent need for an improved multi-faceted heating film and battery cell body for heating the battery cell, so as to improve the heating efficiency, heat preservation performance and safety of the battery cell. Utility Model Content

[0004] The present invention aims to provide a multi-faceted heating film and a battery cell, and to solve the problems of uneven heating, low efficiency and poor heat preservation performance of the battery cell by improving and optimizing the layout of the heating film and the connection method of the battery cell.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A multi-faceted heating film includes a heating film body, which includes a central heating film and side heating films connected to both sides of the central heating film. The central heating film has through holes for positive and negative terminals and explosion-proof valves to pass through. Wear-resistant sheets are bonded to both ends of the side heating films along their long sides. The heating films have gaps at equal intervals and at least two positive and negative terminals. The positive and negative terminals and the heating film body are connected by an electrical circuit.

[0007] A battery cell includes a battery cell body and a multi-sided heating film. The side heating film is adhered to the side of the battery cell body. The through hole of the middle heating film is sleeved on the positive and negative terminals and the explosion-proof valve of the battery cell and adhered to the upper part of the battery cell body. A steel strip is provided at each of the upper and lower ends of the battery cell along the long side direction. The steel strip is clamped on the outside of the wear-resistant sheet.

[0008] The principles and advantages of this scheme are:

[0009] Existing heating films are limited by the structure of the battery cell. Steel strips are attached to both ends of the battery cell along its length, obstructing the heating film. The heating film can only be installed in the area between the steel strips on both sides of the battery cell. The top of the battery cell has protruding positive and negative terminals and an explosion-proof valve. This results in a small heating film area, limited heating zone, uneven heating, and low efficiency. This solution optimizes the external structure of the battery cell by changing the connection sequence of the external steel strips. Simultaneously, the structure of the heating film is optimized, changing from heating film only on both sides to heating film evenly distributed on both sides and the top, increasing the area of ​​the heating film and covering more of the battery cell. This ensures that the top and ends of the battery cell are covered by the heating film, solving the bottleneck problem of low temperature at the ends of the battery cell during heating. Direct power supply via positive and negative terminals ensures safety and reliability. Wear-resistant plates are bonded to both ends of the side heating film along its long side to prevent direct friction between the steel strips and the heating film, thus preventing wear on both the heating film and the battery cell.

[0010] By optimizing the layout of the heating film and the external structure of the battery cell, and changing the connection method between the heating film and the battery cell, the goal of uniform and efficient heating was achieved, providing a new solution for the thermal management of lithium-ion power batteries in new energy vehicles.

[0011] Preferably, as an improvement, the side heating film is further provided with at least two positioning holes and a row of expansion holes. The positioning holes are located on both sides of the middle part of the side heating film along the long side direction, and the expansion holes are elongated through holes, which are arranged at equal intervals along the long side direction of the side heating film.

[0012] Furthermore, the design of the positioning holes and telescopic holes aims to further improve the stability of the side heating film. By using the positioning holes and pin holes, the heating film can be quickly and accurately installed onto the cell surface, reducing the time spent on installation and adjustment. At the same time, fixing the heating film through the positioning holes prevents problems such as loose adhesion and incomplete coverage caused by displacement, ensuring heating stability and effectiveness, and guaranteeing the battery's performance and safety under extreme climatic conditions.

[0013] Preferably, as an improvement, the side heating film is extended along its length on both sides.

[0014] Existing lithium-ion power battery heating systems suffer from a bottleneck problem due to the low temperature of the end cells. Therefore, further improvements are made by extending the length of the side heating film to increase the coverage area. This not only effectively improves the heating efficiency of the battery but also maintains the stability of battery performance in extreme weather conditions, reducing the risk of battery performance degradation caused by uneven temperature.

[0015] Preferably, as an improvement, the central heating film and the side heating film are integrally connected.

[0016] The integrated connection method enhances the stability of the overall structure and extends its service life. At the same time, the integrated connection simplifies the installation process and reduces production costs.

[0017] Preferably, as an improvement, the central heating film and the side heating film are detachably connected, and the heating film body is connected to 6 positive and negative terminals, of which the central heating film and the side heating film are each connected to 2 positive and negative terminals.

[0018] The heating film and side heating films feature a detachable connection design. Each heating film has its own terminal block, and each film is powered independently. This independent control of the input current allows for on-demand heating, enhancing the operability of temperature regulation and enabling more precise thermal management of the lithium-ion battery, resulting in lower energy consumption. Individual current input for each heating film not only improves heating efficiency but also facilitates maintenance and replacement. The detachable connection simplifies maintenance, including subsequent repairs to the battery cell itself. It eliminates the need to remove all three heating films; only one or two need to be removed, effectively reducing the complexity of after-sales service. Furthermore, the use of positive and negative terminals ensures stable current transmission, reducing the risk of uneven heating or failure due to wiring issues, thereby improving the overall reliability and safety of the battery system.

[0019] Preferably, as an improvement, auxiliary positioning pins are bonded to the sidewalls and ends of the battery cell body. The number and position of the positioning pins correspond to the positioning holes, and the length of the positioning pins is equal to the thickness of the heating film.

[0020] By setting auxiliary positioning pins corresponding to the positioning holes, the installation accuracy and efficiency of the heating film can be improved. Since the installation distance between battery cells is limited, the length of the positioning pins should not exceed the thickness of the heating film to avoid scratching the heating films of other battery cells. Ideally, the length of the positioning pins should be equal to the thickness of the heating film.

[0021] Preferably, as an improvement, the end face heating film is also provided with positioning holes, and the short side end of the side heating film is connected and fixed to the end of the battery cell body.

[0022] The positioning holes allow the end-face heating film to be better installed and fixed on the cell body, while the side heating film covers and adheres to both ends of the cell, ensuring uniform heating of the entire cell surface and improving heating efficiency. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the heating film installed on the battery cell body according to Embodiment 1 of this utility model.

[0024] Figure 2 This is a schematic diagram of the structure of the integrated heating film according to Embodiment 1 of this utility model.

[0025] Figure 3 This is a top view of the heating film according to an embodiment of the present invention.

[0026] Figure 4 This is a front view of one side of the heating film in an embodiment of the present invention.

[0027] Figure 5 This is a schematic diagram of the detachable heating film according to Embodiment 2 of this utility model. Detailed Implementation

[0028] The following detailed description illustrates the specific implementation method:

[0029] The reference numerals in the accompanying drawings include: central heating film 1, through hole 101, side heating film 2, expansion joint 201, expansion hole 202, positioning hole 203, positioning pin 204, connecting strip 205, wear-resistant PC sheet 206, battery cell body 3, positive and negative terminals 4, explosion-proof valve 5, wiring terminal 6, and steel strip 7.

[0030] Example 1 is basically as shown in the attached document. Figure 1-4 As shown:

[0031] In this embodiment, a new battery cell is formed by combining an integrated heating film and a battery cell body 3, as shown in the attached figure. Figure 2 As shown, a multi-faceted heating film includes a heating film body, which comprises a central heating film 1 and side heating films 2 respectively connected to both sides of the central heating film 1. The side heating films 2 and the central heating film 1 are rectangular, and the central heating film 1 and the side heating films 2 are integrally connected. This integral connection enhances the stability of the overall structure and improves the service life of the heating film body. Simultaneously, the integral connection simplifies the installation process and reduces production costs. (See attached image) Figure 3 The heating film 1 shown is provided with through holes 101 for the positive and negative pole posts 4 and the explosion-proof valve 5 to pass through. The through holes 101 can not only play a role in positioning and assisting installation, but also make the heating film 1 and the upper surface of the battery cell body 3 fit tightly together, thereby enhancing the heating effect.

[0032] As attached Figure 4As shown, wear-resistant sheets are bonded to both the upper and lower ends of the side heating film 2. In this design, wear-resistant PC sheets 206 are used to prevent the steel strip 7 from directly contacting the heating film, thus preventing damage and extending its service life. Furthermore, if the heating film is damaged and leaks electricity, it could cause a short circuit in the battery cell 3, leading to a safety accident. Therefore, the wear-resistant PC sheets 206 also play a role in preventing such accidents. In addition, the excellent physical and chemical properties of PC material further protect and extend the service life of the heating film. Based on the structural position of the battery cell 3, positioning holes 203 are designed on the side heating film 2. This design provides two positioning holes 203 on both sides of the middle of the side heating film 2. These positioning holes 203 are used to improve the installation accuracy and efficiency of the heating film. To address the breathing effect of the battery cell 3—that is, the periodic expansion and contraction of the battery cell 3—expansion joints 201 are provided at equal intervals at both the upper and lower ends of the side heating film 2. Expansion holes 202 are also provided at equal intervals from left to right in the middle area of ​​the side heating film 2, effectively preventing stress concentration and damage caused by the breathing effect. The two short sides of the side heating film 2 extend outwards, and the two ends after extension become end heating films. The final structure is shown in the attached figure. Figure 4 As shown in the attached document. Figure 1 As shown, the short end of the extended side heating film 2 is connected and fixed to the end of the cell body 3 through the positioning hole 203, solving the heating bottleneck at the end. The middle heating film 1 has two positive and negative terminals 6 at one end. The terminals 6 ensure the stability of current transmission, reducing the risk of uneven heating or failure due to wiring problems, thereby improving the reliability and safety of the overall battery system. Furthermore, the terminals 6 can continuously and stably output a small current to maintain heat preservation, improving the heat preservation performance.

[0033] As attached Figure 1 As shown, a battery cell includes a battery cell body 3 and the aforementioned multi-sided heating film. The side heating film 2 is adhered to the side of the battery cell body 3. The through hole 101 of the middle heating film 1 is sleeved on the positive and negative terminals 4 and the explosion-proof valve 5 of the battery cell and adhered to the upper part of the battery cell body 3. A steel strip 7 is provided at each of the upper and lower ends of the battery cell along the long side direction. The steel strip 7 is clamped to the outside of the wear-resistant PC sheet 206. The steel strip 7 clamps and fixes the heating film and the battery cell body 3 to enhance the overall stability.

[0034] This solution improves the heating efficiency of the battery cell body 3 by increasing the area of ​​the heating film. It changes the external structural connection method of the battery cell body 3 in the existing technology. First, the optimized heating film is fixed on the top and side wall of the battery cell body 3. Then, the steel strip 7 is clamped to both ends of the battery cell body 3 after the heating film is installed, and a new battery cell is formed. This solves the problems of uneven heating, low efficiency and poor heat preservation performance of the existing battery cell.

[0035] The specific implementation method is as follows:

[0036] Align the through hole 101 and positioning hole 203 of the integrated heating film with the explosion-proof valve 5 on top, the positive and negative terminals 4, and the positioning pin 204 on the side, respectively, as shown in the attached diagram. Figure 1 As shown, for ease of observation, only the top of the steel strip 7 is drawn in the figure. The leftmost side heating film 2 at the far right is in an unbent and unattached state. The left and right ends of the heating film 2 are bent and attached to the ends of the battery cell body 3. After fixing, the steel strip 7 is tied to the upper and lower ends along the length of the battery cell body 3. The integrated heating film and the battery cell body 3 are combined by binding with the steel strip 7 to form a new battery cell.

[0037] Example 2 is basically as shown in the attached document. Figure 5 As shown:

[0038] As attached Figure 5 As shown, unlike Embodiment 1, in this embodiment, the central heating film 1 and the side heating film 2 are directly connected by a detachable connecting strip 205.

[0039] The specific implementation method is as follows:

[0040] The parts that are the same as in Embodiment 1 are omitted here. The difference is that after the heating film is pasted on the surface of the battery cell body 3, the middle heating film 1 and the side heating film 2 are connected by the connecting strip 205, and then the steel strip 7 is used to tie and fix them. The detachable heating film and the battery cell body 3 are combined by binding with the steel strip 7 to form a new battery cell.

[0041] The above descriptions are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A multi-faceted heating film, characterized in that: The heating film body includes a central heating film and side heating films connected to both sides of the central heating film. The central heating film and the side heating films are rectangular. The central heating film has through holes for the positive and negative terminals and the explosion-proof valve to pass through. The two ends of the side heating films along the long side direction are bonded with wear-resistant sheets. The heating films have gaps at equal intervals and at least two positive and negative terminals. The positive and negative terminals and the heating film body are connected by circuit.

2. The multi-faceted heating film according to claim 1, characterized in that: The side heating film is also provided with at least two positioning holes and a row of telescopic holes. The positioning holes are located on both sides of the middle part of the side heating film along the long side direction. The telescopic holes are elongated through holes and are arranged at equal intervals along the long side direction of the side heating film.

3. The multi-faceted heating film according to claim 2, characterized in that: The side heating film extends along its length on both sides.

4. A multi-faceted heating film according to any one of claims 1-3, characterized in that: The central heating film and the side heating film are integrally connected.

5. A multi-faceted heating film according to any one of claims 1-3, characterized in that: The central heating film and the side heating film are detachably connected. The heating film body is connected to 6 positive and negative terminals, of which the central heating film and the side heating film are each connected to 2 positive and negative terminals.

6. A battery cell, comprising a cell body, characterized in that: It also includes the multi-faceted heating film as described in any one of claims 1-5, wherein the side heating film is bonded to the side of the battery cell body, the through hole of the middle heating film is sleeved on the positive and negative terminals and the explosion-proof valve of the battery cell and bonded to the upper part of the battery cell body, and a steel strip is provided at each of the upper and lower ends of the battery cell along the long side direction, and the steel strip is clamped on the outside of the wear-resistant sheet.

7. A battery cell according to claim 6, characterized in that: The sidewalls and ends of the battery cell body are bonded with auxiliary positioning pins. The number and position of the positioning pins correspond to the positioning holes, and the length of the positioning pins is equal to the thickness of the heating film.

8. A battery cell according to claim 7, characterized in that: The end heating film is also provided with positioning holes, and the short side end of the side heating film is connected and fixed to the end of the battery cell body.

Images