Battery module heating device and power design method thereof

Abstract

The invention discloses a battery module heating device and a power design method thereof.The battery module heating device comprises a wire assembly and a plurality of heating films, the heating films are used for being attached to different battery cells of a battery module respectively, the heating films are flexibly connected, the wire assembly is arranged between every two adjacent heating films, and the wire assembly is arranged between every two adjacent heating films. The wire assemblies are connected with the two adjacent heating films respectively, and the heating films are connected in series through the wire assemblies. The battery module heating device is divided into a plurality of small-area heating films which can be attached to the corresponding battery cells respectively, even if the battery expands in the later period, all the heating films can also be firmly bonded to the corresponding battery cells, all the heating films do not fall off or swell on the whole, the preheating effect of the battery module is not affected, and the battery module heating device is suitable for large-scale popularization and application. Therefore, the battery module keeps a good working condition, and the service life of the battery module is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of battery heating, and in particular to a battery module heating device and a power design method thereof. Background Art

[0002] When the battery module is running in winter, it is usually necessary to preheat the battery module in advance. In order to achieve effective heating of the battery module, an electric heating film can be attached to the battery module to heat the battery module. The common electric heating film is a whole piece attached to the side of the battery module. Since the battery module is prone to expansion in the later stage, the heating film will fall off, bulge, etc., resulting in a poor preheating effect of the battery module, affecting the charging and discharging of the battery module, which is not conducive to extending the service life of the battery module. Summary of the invention

[0003] In order to solve one of the above-mentioned technical defects, a battery module heating device and a power design method thereof are provided in an embodiment of the present application to solve the problem that the existing heating module is easily deformed with the battery module, resulting in falling off and bulging, thereby affecting the heating effect.

[0004] The present invention adopts the following technical solutions:

[0005] The first object of the present disclosure is to provide a battery module heating device, comprising:

[0006] A plurality of heating films, each of which is used to be attached to different cells of the battery module, and each of which is flexibly connected;

[0007] A conductor assembly is provided between two adjacent heating films, the conductor assembly respectively connects the two adjacent heating films, and the conductor assembly connects the heating films in series.

[0008] Optionally, the battery module heating device includes an elastic strip, which runs through each of the heating films, the elastic strip and the heating film are fixedly connected, and the heating films are connected via the elastic strip.

[0009] Optionally, the battery module heating device comprises a plurality of support bars, each of which is respectively attached to one side of two adjacent heating films along the thickness direction;

[0010] The supporting strip is connected to the elastic strip.

[0011] Optionally, the extension length of the structural segment of the support strip that is attached to the heating film is smaller than the width of the heating film.

[0012] Optionally, the support bar has a lug, and the lug has a through hole;

[0013] The lug passes through the gap between two adjacent heating films, and the elastic strip passes through the through hole of the lug.

[0014] Optionally, the lug is located at a middle position of the support bar along the length direction.

[0015] Optionally, the support strip is in sheet shape, and one side of the support strip along the thickness direction is attached to the heating mold.

[0016] Optionally, the wire assembly includes a plurality of wire groups, two adjacent heating films are connected via a guide group, and two adjacent wire groups are respectively located on two sides perpendicular to the arrangement direction of each heating film.

[0017] Optionally, among the heating films, the power of each heating film gradually increases from the heating film at the middle position to the heating film at the end position.

[0018] The second object of the present application is to provide a power design method for the above-mentioned battery module heating device, comprising:

[0019] Step S1, obtaining the cell characteristic parameters and the reference power parameters of the heating film, wherein the reference power parameters are the power parameters of the heating film at the middle position;

[0020] Step S2, simulating the preheating data of the battery module with the heating film of the reference power according to the battery cell characteristic parameters, the size of the heating film and the reference power parameters;

[0021] Step S3, according to the temperature rise parameter obtained by theoretical calculation, and considering the simulation case, theoretically calculating the power parameter of the heating film at the end;

[0022] Step S4: fitting the power parameters of other heating films according to the reference power parameters and the power parameters of the heating films at the ends.

[0023] By adopting the above technical solution, the present application has the following beneficial effects:

[0024] The battery module heating device of the present application is divided into multiple small-area heating films, which can be respectively attached to the corresponding battery cells. Even when the battery expands in the later stage, each heating film will be firmly bonded to the corresponding battery cell, and the heating films as a whole will not fall off or bulge, which will not affect the preheating effect of the battery module, so that the battery module maintains a good working condition and extends the service life of the battery module.

[0025] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are part of this application and are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention. Obviously, the drawings described below are only some embodiments. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0027] Figure 1 A schematic diagram showing a structure in which a battery module heating device provided in an embodiment of the present application is arranged on a battery module;

[0028] Figure 2 Shows Figure 1 A schematic diagram of the structure after deleting each battery cell and end plate;

[0029] Figure 3 A schematic diagram of the matching structure of the elastic strip and the support strip in the battery module heating device provided in an embodiment of the present application is shown.

[0030] In the figure: 1. heating film; 2. wire group; 3. elastic strip; 4. support strip; 41. lug; 5. thermal insulation foam; 6. end plate; 7. battery cell.

[0031] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but are intended to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0033] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] See also Figures 1 to 3 As shown, an embodiment of the present application provides a battery module heating device, comprising: a wire assembly and a plurality of heating films 1, each of the heating films 1 being used to be respectively attached to different battery cells 7 of the battery module, each of the heating films 1 being flexibly connected, and adjacent heating films 1 being relatively rotatable, the wire assembly being arranged between two adjacent heating films 1, the wire assembly respectively connecting two adjacent heating films 1, and the wire assembly connecting each of the heating films 1 in series.

[0036] The battery module heating device of the present application is divided into a plurality of small-area heating films 1, which can be respectively adhered to the corresponding battery cells 7. For example, they can be adhered to the exposed thickness end faces of the battery cells 7 on the battery module. Even when the battery expands in the later stage, each heating film 1 will be firmly bonded to the corresponding battery cell 7. The heating films 1 as a whole will not fall off or bulge, which will not affect the preheating effect of the battery module, thereby maintaining a good working condition for the battery module and extending the service life of the battery module.

[0037] A battery module heating device can be provided on both sides of the battery module, that is, a heating film 1 of the battery module heating device on the corresponding side is attached to the exposed thickness end surface on both sides of each battery core 7. Thus, the two battery module heating devices can heat both sides of the battery core 7 at the same time, so that both sides of the battery core 7 are evenly heated.

[0038] The exposed thickness end faces of two adjacent battery cells 7 are originally in the same plane. When the two adjacent battery cells 7 are deformed, the thickness end faces of the two battery cells 7 may have a certain angle. At this time, the heating films 1 connected to the thickness end faces of the two battery cells 7 also deform with the deformation of the battery cells 7. Because the two heating films 1 are flexibly connected, a certain angle can be formed between the two heating films 1, and there will be no strong pulling between the two. The heating film 1 will not easily detach from the battery cell 7, nor will it easily bulge, which will not affect the preheating effect of the battery module, so that the battery module maintains a good working condition and extends the service life of the battery module. The two sides of the heating film 1 along the thickness direction are the fitting surface and the exposed surface, respectively. The fitting surface is the inner surface, and a glue layer can be set on the fitting surface to bond to the surface of the battery cell 7.

[0039] In some possible implementation schemes, the battery module heating device includes an elastic strip 3, wherein the elastic strip 3 is parallel to the heating film 1, and the elastic strip 3 is arranged to pass through each of the heating films 1, and the elastic strip 3 is fixedly connected to the heating film 1, and each heating film 1 is connected through the elastic strip 3. A heating wire may be arranged in the heating film 1 to generate heat when power is turned on. The elastic strip 3 may pass through the thickness end surface of the heating film 1, and the part of the elastic strip 3 located on the inner side of the heating film 1 is fixedly connected to the heating film 1 and cannot move relative to the heating film 1. The elastic strip 3 may be an elastic wire that is resistant to high temperatures and has a certain tensile deformation ability. When the two heating films 1 rotate relative to each other to change the angle, the elastic strip 3 will deform under the action of external force to adapt to the deformation of the battery cell 7, thereby effectively avoiding the problem of the heating film 1 falling off and bulging.

[0040] In order to stably connect two adjacent heating films 1, each battery module heating device may be provided with at least two elastic strips 3, each elastic strip 3 is arranged in parallel and at intervals, and each elastic strip 3 may be respectively connected to a corresponding number of heating films 1. It should be noted that each elastic strip 3 on the same straight line may be a complete elastic strip 3, or may be a plurality of independent elastic segments, each elastic segment being respectively connected to two or more adjacent heating films 1.

[0041] It should be noted that there is a certain distance between two adjacent heating films 1, so that the elastic strip 3 has a sufficient extension length, thereby increasing the extension length of the elastic strip 3 between the two adjacent heating films 1, improving the deformation capacity, and avoiding the elastic strip 3 from breaking due to excessive deformation. The elastic strip 3 can be a rubber band, rubber or other elastic structure, and the present application does not limit the material and principle of the elastic strip 3.

[0042] In some possible implementations, the battery module heating device includes a plurality of support bars 4 , each of the support bars 4 is respectively attached to one side of two adjacent heating films 1 along the thickness direction, and the support bars 4 are connected to the elastic bars 3 .

[0043] The support bar 4 has a certain rigidity and is located on the side of the heating film 1 away from the battery cell 7. The setting of the support bar 4 makes each heating film 1 have a relatively integrated effect, which facilitates the one-time adjustment of the positions of all the heating films 1 and the pasting of each heating film 1 on the corresponding battery cell 7, thereby improving the assembly efficiency. However, adjacent heating films 1 can still move relative to each other, which does not affect the independence of each heating film 1.

[0044] The support strip 4 and the heating film 1 are not connected. The support strip 4 can be connected to the elastic strip 3 so that it will not be easily separated from each heating film 1, so that each heating film 1 can be driven and operated together.

[0045] In some possible implementations, the extension length of the structural section of the support bar 4 attached to the heating film 1 is less than the width of the heating film 1. That is, the length of the support bar 4 cannot be greater than the width of two heating films 1, and can be close to the width of one heating film 1. The support bar will not cause the two adjacent heating films to move relative to each other.

[0046] In some possible embodiments, the support bar 4 has a lug 41, and the lug 41 has a through hole. The lug 41 passes through the gap between two adjacent heating films 1, and the elastic strip 3 passes through the through hole of the lug 41, thereby achieving effective connection between the elastic strip 3 and the support bar 4, and the connection structure is simple, the connection stability is good, the space is fully utilized, and the production is convenient.

[0047] Insulating foam 5 is arranged between adjacent battery cells 7 in the battery module, and the gap between adjacent heating films 1 faces the insulating foam 5 , that is, the lug 41 faces the insulating foam 5 .

[0048] In some possible implementations, the lug 41 is located in the middle of the support bar 4 along the length direction, that is, the middle of the support bar 4 along the length direction is opposite to the gap between two adjacent heating films 1. Two or more support bars 4 can be arranged between each two adjacent heating films 1, and each support bar 4 is parallel to each other. The number of support bars 4 between two adjacent heating films 1 can be opposite to the number of elastic bars 3 of the heating device, so as to facilitate connection to the corresponding elastic bars 3 respectively.

[0049] Optionally, the support bar 4 is in sheet shape, and one side of the support bar 4 along the thickness direction is attached to the heating film 1. The support bar 4 may have a certain deformation capability. The support bar 4 may be a metal bar, for example, the support bar 4 may be a steel sheet, and the elastic bar 3 connects the steel sheets in series, and there is a certain gap between the steel sheets, so that the heating films 1 connected in series can be attached to the module as a whole during installation, which is more convenient to operate.

[0050] In some possible implementation schemes, the wire assembly includes a plurality of wire groups 2 , two adjacent heating films 1 are connected via one wire group, and two adjacent wire groups 2 are respectively located on two sides perpendicular to the arrangement direction of each heating film 1 .

[0051] The gap between adjacent heating films 1 is small and is not suitable for setting up the wire group 2. In the present application, the wire group 2 is arranged on both sides perpendicular to the arrangement direction of each heating film 1, that is, on both sides of the height direction of the battery cell 7, and the two adjacent wire groups 2 are arranged on both sides of the elastic strip 3 without interfering with each other. The layout of the wire group 2 is regular and orderly, which is more scientific and avoids the problem of redundancy and clutter.

[0052] In some possible implementation schemes, in each of the heating films 1 , the power of each of the heating films 1 gradually increases from the heating film 1 at the middle position to the heating film 1 at the end position.

[0053] Both ends of each battery cell 7 of the battery module are provided with end plates 6, which are usually made of aluminum alloy. The end plates 6 are in contact with the water-cooling plate of the pack (battery pack). The end plates 6 have strong thermal conductivity, which results in the temperature of the battery cells 7 at both ends of the battery module being relatively low during the preheating process, and the temperature of the battery cell 7 in the middle of the battery module being relatively high.

[0054] In order to make the preheating temperature of each battery cell 7 of the battery module uniform, the battery module heating device provided in the present application provides a plurality of heating films 1, each heating film 1 is connected in series in sequence, and adjacent heating films 1 are electrically connected through a wire group 2. Taking the battery cell 7 in the middle position of the battery module as a reference, the power of the heating film 1 increases step by step in the direction of both sides to achieve the purpose of preheating the battery module to a uniform temperature.

[0055] In order to further scientifically improve the heating rate and temperature uniformity, the present application can use simulation input for the power of each heating film 1, continuously iterate and optimize, and accurately determine the power of each heating film 1.

[0056] Specifically, the present application provides a power design method for the above-mentioned battery module heating device as follows, including:

[0057] Step S1, obtaining characteristic parameters of the battery cell 7 and reference power parameters of the heating film 1, wherein the reference power parameter is the power parameter of the heating film 1 at the middle position;

[0058] The characteristic parameters of the battery cell 7, such as specific heat capacity, density, thermal conductivity, etc., are all known data, and the characteristic parameters of the battery cell 7 can be directly obtained. The reference power parameters of the heating film 1 can be obtained by theoretical calculation. The reference power parameters of the heating film 1 can be understood as the power parameters of the corresponding heating film 1 calculated based on the parameters such as specific heat capacity, density and volume of the battery cell 7, and the temperature rise requirement parameters required by the battery cell 7 (such as how many degrees of preheating are required per hour). This power parameter can be understood as the power parameter of the heating film 1 for the battery cell 7 in the middle position of the battery module.

[0059] Step S2, according to the characteristic parameters of the battery cell 7, the size of the heating film 1 and the reference power parameters, simulate the simulation data of preheating the battery module with the heating film 1 at the reference power;

[0060] The above step S1 is a theoretical calculation for a single battery cell 7. In this step S2, the entire battery module is further simulated, that is, the simulation data is assumed to be after all the battery cells 7 in the battery module are attached to the heating film 1 with the reference power. The simulation data can obtain the minimum temperature, maximum temperature, average temperature of each battery cell 7, and the temperature difference data of the battery cell 7, etc.

[0061] Step S3, according to the temperature rise parameter obtained by theoretical calculation, and considering the simulation case, theoretically calculating the power parameter of the heating film 1 at the end;

[0062] In this step, the temperature rise data of the middle battery cell 7 and the end battery cell 7 can be obtained respectively according to the simulation data. There is a temperature difference between the middle battery cell 7 and the end battery cell 7. According to the temperature difference, the power parameters of the corresponding end heating film 1 to eliminate the temperature difference can be determined.

[0063] Step S4: fitting the power parameters of other heating films 1 according to the reference power parameters and the power parameters of the heating films 1 at the ends.

[0064] According to step S4, the power parameters of all the heating films 1 can be fitted, thereby relatively accurately determining the power parameters of each heating film 1 of the battery module heating device.

[0065] After step S4, step S5 may be further included. Step S5 may be an iteration of the above steps to determine whether the temperature difference of the battery module is good. The iteration may be terminated until the battery module preheating process has good temperature uniformity.

[0066] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this patent can make some changes or modify the technical contents suggested above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the solution of the present invention.

Claims

1. A battery module heating device, characterized in that: include: A plurality of heating films, each of which is used to be attached to different cells of the battery module, and each of which is flexibly connected; A conductor assembly is provided between two adjacent heating films, the conductor assembly respectively connects the two adjacent heating films, and the conductor assembly connects the heating films in series.

2. The battery module heating device according to claim 1, characterized in that: It comprises an elastic strip, which runs through each of the heating films, the elastic strip is fixedly connected to the heating film, and each heating film is connected through the elastic strip.

3. The battery module heating device according to claim 2, characterized in that: It comprises a plurality of support bars, each of which is respectively attached to one side of two adjacent heating films along the thickness direction; The supporting strip is connected to the elastic strip.

4. The battery module heating device according to claim 3, characterized in that: The extension length of the structural section of the support strip that is attached to the heating film is smaller than the width of the heating film.

5. The battery module heating device according to claim 4, characterized in that: The support bar has a lug, and the lug has a through hole; The lug passes through the gap between two adjacent heating films, and the elastic strip passes through the through hole of the lug.

6. The battery module heating device according to claim 5, characterized in that: The lug is located at the middle of the support bar along the length direction.

7. The battery module heating device according to claim 6, characterized in that: The support strip is in sheet shape, and one side of the support strip along the thickness direction is attached to the heating mold.

8. The battery module heating device according to claim 1, characterized in that: The wire assembly includes a plurality of wire groups, two adjacent heating films are connected via a guide group, and two adjacent wire groups are respectively located on two sides perpendicular to the arrangement direction of the heating films.

9. The battery module heating device according to claim 1, characterized in that: In each of the heating films, the power of each of the heating films gradually increases from the heating film at the middle position to the heating film at the end position.

10. The power design method of the battery module heating device according to any one of claims 1 to 9, characterized in that: include: Step S1, obtaining the cell characteristic parameters and the reference power parameters of the heating film, wherein the reference power parameters are the power parameters of the heating film at the middle position; Step S2, simulating the preheating data of the battery module with the heating film of the reference power according to the battery cell characteristic parameters, the size of the heating film and the reference power parameters; Step S3, according to the temperature rise parameter obtained by theoretical calculation, and considering the simulation case, theoretically calculating the power parameter of the heating film at the end; Step S4: fitting the power parameters of other heating films according to the reference power parameters and the power parameters of the heating films at the ends.

Images