CN214254546U - Heating structure and battery pack - Google Patents

Abstract

The utility model discloses a heating structure and battery package, this heating structure is used for heating the battery of battery package. The heating structure is provided with heating areas which are arranged in sequence, and the heating power of the heating areas is gradually reduced from two ends to the middle. Heating structure is injectd through the power of generating heat to different district that generates heat, and then realizes that the electric core on different positions keeps the same temperature, and then improves the temperature uniformity of battery package.

Description

Heating structure and battery pack

Technical Field

The utility model relates to a battery technology field, in particular to heating structure and battery package.

Background

New energy automobiles are rapidly developed in recent years and widely applied all over the world. The core of a new energy automobile is a battery pack, and when the new energy automobile is used in a low-temperature environment such as a high-altitude area and winter, the battery pack is generally required to be heated in order to improve the performance of the battery pack.

The existing heating scheme for the battery pack is mainly to arrange a PI (Polyimide) heating film on the surface of the battery pack, and the PI heating film is generally in a structure that a layer of heating structure is sandwiched between two insulating layers. Because PI heating film is flexible structure, need add fixed structure spare to the holistic thermal management cost of battery package has been increased, and current PI heating film can't realize the heating temperature uniformity nature of electric core.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the technical problem that will solve is: to the problem that the heating temperature uniformity of electric core in the battery package can not be realized to current heating structure, provide a heating structure and battery package.

In order to solve the technical problem, the first aspect of the present invention provides a heating structure for heating a battery of a battery pack, the heating structure has a plurality of heating areas arranged in order, and a plurality of heating power of the heating areas is gradually reduced from both ends to the middle.

In some embodiments, the heating structure includes a substrate, and a heating layer and a heat conduction layer which are arranged on the same layer on the substrate and are connected with each other, and the heating layer and the heat conduction layer constitute a plurality of the heat generating regions.

In some embodiments, the heating layer has a plurality of hollow spaces, the hollow spaces are sequentially arranged at intervals, the heat conduction layer is accommodated in the hollow spaces, and the heat conduction layer and the part of the heating layer surrounding the hollow spaces to form the heating area.

In some embodiments, in the plurality of hollowed-out spaces, the volume of the heat conduction layer gradually decreases from two ends to the middle.

In some embodiments, in the plurality of hollowed-out spaces, the heat conducting layer has the same thickness and length, and the width gradually decreases from two ends to the middle.

In some embodiments, the heating layer has a positive electrode connecting portion, a negative electrode connecting portion, and a plurality of first branch portions located between the positive electrode connecting portion and the negative electrode connecting portion, the positive electrode connecting portion, the negative electrode connecting portion and the first branch portions define the hollow space together, the first branch portions connect the positive electrode connecting portion and are insulated from the negative electrode connecting portion, the first branch portions connect the heat conducting layer, the heat conducting layer is insulated from the positive electrode connecting portion and is connected to the negative electrode connecting portion, and an electric current flows into the first connecting portion through the positive electrode connecting portion and flows into the negative electrode connecting portion through the heat conducting layer to form a backflow.

In some embodiments, the heating layer has a positive electrode connecting portion, a negative electrode connecting portion and a plurality of first branch portions located in the middle of the positive electrode connecting portion and the negative electrode connecting portion, the positive electrode connecting portion the negative electrode connecting portion and the first branch portions define the hollow space together, the first branch portions are connected to the heat conducting layer, and the first branch portions and the heat conducting layer are insulated from the negative electrode connecting portion, the heating structure further has a second branch portion located in the hollow space, the second branch portion is connected to the negative electrode connecting portion and insulated from the positive electrode connecting portion, the heat conducting layer is connected to the second branch portion, current flows into the first connecting portion through the positive electrode connecting portion, and after passing through the heat conducting layer and the second branch portion, the current flows into the negative electrode connecting portion to form a backflow.

In some embodiments, the heating layer further has a third branch portion located in the hollow space, the third branch portion is insulated from the positive electrode connecting portion and the negative electrode connecting portion, respectively, and the third branch portion is connected to the heat conducting layer.

In some embodiments, the heat conducting layer is made of any one of graphene, a graphene composite material and carbon nanotubes, and the heat conductivity of the heating layer is smaller than that of the heat conducting layer.

In some embodiments, the base plate is a bottom plate of the battery pack tray assembly and/or a top plate of the battery pack upper cover.

In a second aspect, the present invention further provides a battery pack, which includes the above-mentioned heating structure.

According to the utility model discloses a beneficial effect does: the application discloses a heating structure for heating the battery of battery package. The heating structure is provided with heating areas which are arranged in sequence, and the heating power of the heating areas is gradually reduced from two ends to the middle. Heating structure is injectd through the power of generating heat to different district that generates heat, and then realizes that the electric core on different positions keeps the same temperature, and then improves the temperature uniformity of battery package.

Drawings

Fig. 1 is a schematic view of a heating structure according to an embodiment of the present invention.

Fig. 2 is an exploded view of a heating structure according to an embodiment of the present invention.

Fig. 3 is a schematic plan view of a heating layer and a heat conducting layer according to an embodiment of the present invention.

Fig. 4 is a schematic plan view of a heating layer and a heat conducting layer according to another embodiment of the present invention.

Fig. 5 is an exploded view of a battery pack according to an embodiment of the present invention.

The reference numerals in the specification are as follows:

10. a battery pack;

100. a heating structure; 110. a heat generating region; 120. a heating layer; 121. a positive electrode connecting part; 1211. a positive terminal; 122. a negative electrode connecting part; 1221. a negative terminal; 123. a first branch portion; 124. a second branch portion; 125. a third branch portion; 130. a heat conductive layer; 140. an insulating layer; 150. hollowing out a space; 160 a substrate;

200. a battery module; 210. a tray assembly;

s1, a first heat-generating area; s2, a second heating area; s3, a third heating area; s4, a fourth heat generation area.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

For convenience of description, in the embodiment of the present application, as shown in fig. 1 to 4, the first direction is a direction in which the hollow spaces are sequentially arranged at intervals, and is an X direction in the drawing; the second direction is the Y direction in the drawing; the third direction is a hollow space which is the Z direction in the attached drawing. The first direction, the second direction and the third direction are perpendicular to each other. The size of the heat conduction layer along the first direction is the width of the heat conduction layer; the size of the heat conduction layer along the second direction is the length of the heat conduction layer; the dimension of the heat conductive layer in the third direction is the thickness of the heat conductive layer.

In a first aspect, embodiments of the present application provide a heating structure 100 for heating a battery of a battery pack. The heating structure 100 has a plurality of heating regions 110 arranged in sequence, and the heating power of the plurality of heating regions 110 gradually decreases from two ends to the middle along the arrangement direction of the plurality of heating regions 110. The arrangement direction of the plurality of heat generating regions 110 is a first direction. The heating structure 100 in the embodiment of the present application further realizes the temperature uniformity of the heating structure 100 by providing a plurality of heating areas 110 with different heating powers.

Specifically, in the related art, in the whole battery pack, since the electric core in the battery pack has a plurality of and arranges along a certain order, the heat dissipation effect of the electric core near the edge in the battery pack is better than the heat dissipation effect of the electric core arranged at the center of the battery pack. Therefore, if the conventional PI heating film is used for heating, the temperature equalization is performed when the whole PI heating film is heated, but for the battery cells in the battery pack, the battery cells at different positions have different heating effects, and the conventional PI heating film cannot meet the requirement of the temperature equalization of the battery cells in the battery pack.

Moreover, the battery pack body in the whole vehicle is at the edge-covered position, the influence of the environment on the battery at the edge is large, so that more heat is dissipated, and the battery in the middle of the battery pack has large thermal resistance to the environment and small heat dissipation loss, so that the heating structure 100 at the positions of the vehicle head and the vehicle tail needs to be adjusted to control the temperature consistency of the battery pack, so that the resistance of the heating structure 100 at the middle of the battery pack is reduced, and the resistance of the heating structure corresponding to the battery pack at the positions of the vehicle head and the vehicle tail is increased.

Therefore, the embodiment of the application provides a heating structure 100, and this heating structure 100 is through setting up the district 110 that generates heat of a plurality of different heating powers, and then realizes reaching the same heating effect to the electric core of battery package different positions homoenergetic, realizes the temperature uniformity of battery package.

Still further, as shown in fig. 1, in order to satisfy that the heat dissipation effect of the battery cell near the edge position inside the battery pack is better than the heat dissipation effect of the battery cell near the center position, the heating structure 100 disclosed in the embodiment of the present application defines that the plurality of heating areas 110 are gradually reduced from both ends to the middle along the arrangement direction of the plurality of heating areas 110, and further, the temperature equalization capability of the heating structure 100 to the battery pack is improved in a targeted manner. In the embodiment of the present application, S1 represents a first heat generation region, S2 represents a second heat generation region, and S3 represents a third heat generation region; s4 represents a fourth heat generation area. In order to satisfy the effect of uniform heating of the battery cell, the heating power requirement (P) of the heating region 110_S1And P_S4）> （P_S2And P_S3) (ii) a That is, the heating power of the two end heating regions 110 gradually decreases toward the middle heating region 110.

In the embodiment of the present application, as shown in fig. 2 to 3, the heating structure 100 includes a substrate, and a heating layer 120 and a heat conducting layer 130 disposed on the substrate in the same layer and connected to each other, wherein the heating layer 120 and the heat conducting layer 130 together form a plurality of heat generating regions 110.

Specifically, the heating layer 120 is generally made of a high-resistance material, and generates heat according to the resistance heating principle, so as to achieve the effect of heating the battery core. Generally, the material of the heating layer 120 is generally selected from copper, steel, PTC heater, etc., and its resistance value is set according to the required heating power, and is not particularly limited.

The heat conductive layer 130 is used to conduct heat, i.e., the heat of the heating layer 120 to a larger area of the heat conductive layer 130. The heat conducting layer 130 may be a material having a higher thermal conductivity than the heating layer 120, and optionally, the material of the heat conducting layer 130 is any one of graphene, a graphene composite material, and carbon nanotubes, and the thermal conductivity of these materials is higher than that of a general metal heat conducting material or a PTC heating body, that is, the thermal conductivity of the heating layer 120. For the carbon nanotube, the thermal conductivity is lower than that of the graphene and the graphene composite material, but the carbon nanotube as the heat conduction layer 130 can generate and conduct heat, that is, not only can the heat of the heating layer 120 be conducted out, but also the carbon nanotube itself can generate heat.

In an embodiment of the present application, when the heat conducting layer 130 is used only for the heat conducting function, i.e. the two are in physical contact, no current can flow, and the heat of the heating layer 120 is conducted to the heat conducting layer 130 through the contact position of the two. Heating structure 100 can then realize the temperature uniformity of heating structure to electric core through the volume that changes zone of heating 120 this moment, follows the district 110 orientation of arranging that generates heat promptly, and the volume of zone of heating 120 reduces gradually to the centre along both ends. The change in the volume of the heating layer 120 affects the change in the resistance of the heating layer 120, and thus the change in the heating power of the heating layer 120. The heating structure 100 is provided with the heat conducting layer 130, which mainly aims at reducing the weight of the heating structure 100 and increasing the propagation rate of the heating structure 100.

In another embodiment of the present application, when the heat conductive layer 130 is capable of conducting heat and generating heat, i.e., the two are electrically connected, an electric current flows between the two. The heat conducting layer 130 in this way can also be excited by the current to generate heat, that is, the heat conducting layer 130 generates heat and conducts heat at the same time, and the heat conducted by the heating layer 120 is superposed, so that the temperature can be increased more quickly. At this moment, the heating structure 100 can further realize the temperature uniformity of the heating structure to the electric core by changing the volume of the heat conducting layer 130, that is, along the arrangement direction of the heating area 110, the volume of the heat conducting layer 130 is gradually reduced from two ends to the middle. The volume change of the heat conduction layer 130 affects the change of the resistance of the heating layer 120, and thus the change of the heating power of the heat generation region 110.

In other embodiments of the present application, the heat conducting layer 130 and the heating layer 120 may be changed according to actual needs, that is, the volume change of the heating layer 120 and/or the heat conducting layer 130 is adjusted according to the change of the heat generating power of different heat generating regions 110, which is not limited thereto.

In the embodiment of the present application, the heating layer 120 and the heat conduction layer 130 are disposed on the same layer, so that the occupied space in the thickness direction can be reduced, the heating layer 120 and the heat conduction layer 130 can cover a larger area as a whole, and the uniformity of the temperature is also well affected.

The specific structure of the same layer arrangement of the heating layer 120 and the heat conductive layer 130 may be any feasible structure. The heating layer 120 and the heat conduction layer 130 can be formed on the heat conduction insulating adhesive layer through etching or die cutting, the process is mature, the formed structure is uniform, the extremely small size interval can be carved, and the sudden change of the local heating and temperature equalizing effects can be reduced conveniently.

In the present embodiment, as shown in fig. 2, the heating layer 120 and the heat conduction layer 130 further have insulating layers 140 on both sides in the third direction. The insulating layer 140 may be a heat conducting insulating layer for rapidly conducting the heating layer 120 and the heat conducting layer 130 away and insulating the connected devices.

In the embodiment of the present application, as shown in fig. 2, the heating layer 120 and the heat conduction layer 130 are provided on the substrate 160, and the substrate 160 serves to support and protect the heating layer 120 and the heat conduction layer 130. This base plate 160 has certain intensity, consequently, when heating structure 100 is integrated at tray subassembly and/or battery package upper cover, base plate 160 can regard as tray subassembly's bottom plate and/or the roof of battery package upper cover, and then realize the integration of heating structure 100 and tray subassembly and/or battery package upper cover, make whole tray subassembly and/or battery package upper cover design more nimble, reduce the reliance to the Z direction, further improve energy utilization, reduce assembly cost, the inefficacy risk when pasting is reduced.

Further, the insulating layer 140, in which the heating layer 120 and the heat conductive layer 130 are disposed adjacent to the substrate 160, may also be a heat conductive insulating adhesive layer, by which the heating layer 120 and the heat conductive layer 130 are fixed on the substrate 160.

In the embodiment of the present application, as shown in fig. 2 to 3, the heating layer 120 has an empty space 150, the empty space 150 accommodates the heat conducting layer 130, and the heat conducting layer 130 is connected to the heating layer 120. The heat conducting layer 130 located in the hollow space 150 and the part of the heating layer 120 enclosing to form the hollow space 150 form the heat generating region 110. In other words, the heating layer 120 wraps around the heat conducting layer 130, the heating layer 120 can be transmitted to the heat conducting layer 130 through the periphery of the heat conducting layer 130, the heating layer 120 and the heat conducting layer 130 define the heating area 110 together, and the temperature uniformity of the heating structure is further realized.

Further, there are a plurality of fretwork spaces 150 of heating layer 120, and a plurality of fretwork spaces 150 interval sets up in proper order, all holds heat-conducting layer 130 in a plurality of fretwork spaces 150.

In the present embodiment, the heating layer 120 is electrically connected to the heat conducting layer 130, i.e. an electric current can flow through the heating layer 120 into the heat conducting layer 130. The heating layer 120 changes the spatial arrangement and the volume arrangement of the hollow space 150, so as to achieve uniform temperature of the heating structure. That is, the volume of the heat conductive layer 130 in the plurality of receiving areas gradually decreases from the two ends to the middle along the arrangement direction of the hollow spaces 150.

Specifically, the formula R = ρ × L/S = (ρ × L)/(δ × d) is calculated from the resistance of the conductor, where R is the resistance, ρ is the volume resistivity of the heat generation layer, L is the length/width/thickness in the prescribed direction, d is the length/width/thickness in the prescribed direction, δ is the length/width/thickness in the prescribed direction, and S is the area of the heat generation layer in the prescribed direction. When the length and the thickness are constant in the first direction, the width is in direct proportion to the resistivity; when the length and the width are constant along the third direction, the thickness is proportional to the resistivity. Therefore, the volume of the heat conducting layer 130 is changed to change the resistance of the heat conducting layer 130, and the heat generating power of different heat generating areas 110 is changed.

Optionally, in the plurality of hollow spaces 150, the lengths of the plurality of heat conduction layers 130 are the same, and the thicknesses of the plurality of heat conduction layers 130 gradually decrease from two ends to the middle along the first direction, that is, the size of the heat conduction layer 130 is changed by changing the thickness of the heat conduction layer 130 under the condition of fixing the sizes of the hollow spaces 150, so that the different heat generation powers of the different heat generation areas 110 are realized.

Optionally, as shown in fig. 3, in the plurality of hollowed-out spaces 150, the thicknesses and the lengths of the plurality of heat conducting layers 130 are the same, and the widths of the plurality of heat conducting layers 130 are gradually reduced from two ends to the middle, that is, the widths of the hollowed-out spaces 150 are changed while the thicknesses of the heat conducting layers 130 are fixed, so as to change the size of the heat conducting layers 130, and further achieve different heat generating powers in different heat generating areas 110. Specifically, the length of W1 is greater than the length of W2. W1 indicates the width of the first hollowed-out space 150; w2 indicates the width of the second hollow space 150, wherein the first hollow space 150 is located at two ends of the heating layer 120, and the second hollow space 150 is located in the middle of the heating layer 120. The arrangement method can also ensure the smoothness of the heating structure 100, and is more beneficial to using battery packs in different situations.

In another embodiment of the present application, the material of the heat conducting layer 130 may be different in different heat generating areas 110. For example, in the direction of arranging along a plurality of heating areas, the resistance of the material of the two end heat conduction layers 130 is greater than the resistance of the material of the middle heat conduction layer 130, so that the heating power of the two end heat conduction layers 130 is greater than the heating power of the middle heat conduction layer 120, and the temperature uniformity inside the battery pack is further realized. And the volumes of the heat conduction layers 130 in different heat generation areas 110 may not change sequentially along the arrangement direction of the heat generation areas.

In an embodiment of the present application, as shown in fig. 3 to 4, the heating layer 120 has a positive electrode connection part 121, a negative electrode connection part 122, and a plurality of first branch parts 123 located in the middle of the positive electrode connection part 121 and the negative electrode connection part 122. The positive electrode connection portion 121 and the negative electrode connection portion 122 are insulated from each other. The positive electrode connecting portion 121, the negative electrode connecting portion 122 and the first branch portion 123 define a hollow space 150. The heat conducting layer 130 is disposed in the hollow space 150. The first branch portion 123 is connected to the positive electrode connection portion 121, the first branch portion 123 is connected to the heat conduction layer 130 and is insulated from the negative electrode connection portion 122, and the heat conduction layer is insulated from the positive electrode connection portion 121 and is connected to the negative electrode connection portion 122. The current flows into the first connection portion through the positive electrode connection portion 121, and flows back to the negative electrode connection portion 122 through the heat conductive layer.

Further, the positive electrode connection part 121 has a positive electrode terminal 1211; the negative connection 122 has a negative terminal 1221 the positive terminal 1211 and the negative terminal 1221 are connected to the positive and negative poles of the cell for passing cell current into the heating layer 120.

In another embodiment of the present application, as shown in fig. 3 to 4, the heating layer 120 has a positive electrode connection part 121, a negative electrode connection part 122, and a plurality of first branch parts 123 located in the middle of the positive electrode connection part 121 and the negative electrode connection part 122. The positive electrode connection portion 121 and the negative electrode connection portion 122 are insulated from each other. The positive electrode connecting portion 121, the negative electrode connecting portion 122 and the first branch portion 123 define the hollow space 150, and the heat conducting layer 130 is disposed in the hollow space 150. The first branch portion 123 is connected to the heat conducting layer 130, and the first connecting portion and the heat conducting layer are insulated from the negative electrode connecting portion 122, the heating structure 100 further has a second branch portion 124 located in the hollow space 150, the second branch portion 124 is connected to the negative electrode connecting portion 122 and insulated from the positive electrode connecting portion 121, and the heat conducting layer 130 is connected to the second branch portion 124. The current flows into the first connection portion through the positive electrode connection portion 121, passes through the heat conductive layer and the second branch portion 124, and then flows into the negative electrode connection portion 122 to be returned.

In the embodiment of the present application, as shown in fig. 3 to 4, the heating layer 120 further has a third branch portion 125 located in the hollow space 150, the third branch portion 125 is insulated from the positive electrode connection portion 121 and the negative electrode connection portion 122, respectively, and the third branch portion 125 is connected to the heat conduction layer 130. The electric current flowing into the heat conductive layer 130 can flow into the other heat conductive layer 130 through the third branch portion 125. The third branch 125 of the heating layer 120 is mainly provided to enhance the strength of the heating structure 100, so that the heating structure 100 is not easily deformed.

Specifically, in an embodiment of the present application, as shown in fig. 4, the heating structure 100 has four heat generating areas 110, and each heat generating area 110 is composed of a positive electrode connecting portion 121, a negative electrode connecting portion 122, and a first branch portion 123. In the first to third heat generation regions S1 to S3, the third branch portion 125 is further provided in the hollow space 150, and the heat conductive layer 130 is connected to the negative electrode connection portion 122. Specifically, in the first heat generation region S1, the second heat generation region S2, and the third heat generation region S3, the current flows from the positive electrode connection portion 121 into the first branch portion 123, and flows into the negative electrode connection portion 122 through the heat conductive layer 130, the third branch portion 125, and the heat conductive layer 130. In the fourth heat generating region S4, the second branch portion 124 is provided in the hollow space 150, and the heat conducting layer 130 is insulated from the negative electrode connecting portion 122 and connected to the second branch portion 124. Specifically, the current flows from the positive electrode connecting portion 121 into the first branch portion 123, and flows into the negative electrode connecting portion 122 through the heat conductive layer 130 and the second branch portion 124.

In particular, the first branch portion 123, the second branch portion 124, and the third branch portion 125 may be disposed in the hollow space 150, and when the second branch portion 124 is disposed in the hollow space 150, the heat conducting layer 130 is insulated from the negative electrode connecting portion 122 and connected to the second branch portion 124.

In a second aspect, the present application further provides a battery pack, where the battery pack includes the above-mentioned heating mechanism 100, and the heating mechanism 100 heats an electric core in the battery pack to implement temperature uniformity of the battery pack.

In this embodiment, it can be understood that the battery core may be a single battery or a battery module. And in general, the battery cell may be a lithium ion battery, however, the battery cell may be a battery made of other materials, such as a solid-state battery, and the like. In addition, the battery core can also be a square hard shell battery or a soft package battery. In the embodiment of the present application, a battery cell is not further limited, and a battery in the battery field can be regarded as the battery cell described in the embodiment of the present application, and can be heated by the heating structure in the embodiment of the present application.

In the embodiment of the present application, as shown in fig. 5, the substrate of the heating structure is used as the upper cover of the battery pack and/or the tray assembly, so that the energy density of the battery pack is further improved, the size in the thickness direction is reduced, and the assembly cost is reduced, and the substrate 160 has a certain strength, so that when the heating structure 100 is integrated in the upper cover of the tray assembly 210 and/or the battery pack, the substrate 160 can be used as the bottom plate 210 of the tray assembly and/or the top plate of the upper cover of the battery pack, thereby realizing the integration of the heating structure 100 with the upper cover of the tray assembly 210 and/or the battery pack, making the whole tray assembly 210 more flexible in design, reducing the dependence on the Z direction, further improving the energy utilization rate, reducing the assembly cost, and reducing the failure risk during the pasting.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship indicated based on the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the scope of the present invention.

Claims (11)

1. The heating structure is used for heating batteries of a battery pack and is characterized by comprising a plurality of heating areas which are sequentially arranged, and the heating power of the heating areas is gradually reduced from two ends to the middle.

2. The heating structure according to claim 1, wherein the heating structure comprises a substrate, and a heating layer and a heat conducting layer which are arranged on the substrate in the same layer and connected with each other, wherein the heating layer and the heat conducting layer constitute a plurality of the heat generating regions.

3. The heating structure of claim 2, wherein the heating layer has a plurality of hollow spaces, the hollow spaces are sequentially spaced apart from one another, the heat conducting layer is accommodated in the hollow spaces, and the heat conducting layer and the heating layer surrounding the hollow spaces form the heat generating region.

4. The heating structure according to claim 3, wherein the volume of the heat conductive layer is gradually reduced from both ends to the middle in the plurality of hollow spaces.

5. The heating structure according to claim 4, wherein the heat conductive layer has the same thickness and length and the width gradually decreases from the ends to the center in the plurality of hollow spaces.

6. The heating structure according to claim 3, wherein the heating layer has a positive electrode connecting portion, a negative electrode connecting portion, and a plurality of first branch portions located between the positive electrode connecting portion and the negative electrode connecting portion, the positive electrode connecting portion, the negative electrode connecting portion and the first branch portions together define the hollow space, the first branch portions are connected to the positive electrode connecting portion and are insulated from the negative electrode connecting portion, the first branch portions are connected to the heat conductive layer, the heat conductive layer is insulated from the positive electrode connecting portion and is connected to the negative electrode connecting portion, and an electric current flows into the first branch portions through the positive electrode connecting portion and flows into the negative electrode connecting portion through the heat conductive layer to form a return current.

7. The heating structure according to claim 3, wherein the heating layer has a positive electrode connecting portion, a negative electrode connecting portion, and a plurality of first branch portions located intermediate the positive electrode connecting portion and the negative electrode connecting portion, the positive electrode connecting part, the negative electrode connecting part and the first branch part define the hollow space together, the first branch part is connected with the heat conducting layer, the first branch part and the heat conduction layer are insulated with the cathode connecting part, the heating structure is also provided with a second branch part positioned in the hollow space, the second branch portion is connected to the negative electrode connecting portion and insulated from the positive electrode connecting portion, the heat conductive layer is connected to the second branch portion, and current flows into the first branch portion through the positive electrode connecting portion, and the heat conduction layer and the second branch part flow into the negative electrode connecting part to form backflow.

8. The heating structure according to claim 6 or 7, wherein the heating layer further has a third branch portion located in the hollow space, the third branch portion being insulated from the positive electrode connecting portion and the negative electrode connecting portion, respectively, the third branch portion being connected to the heat conductive layer.

9. The heating structure of claim 2, wherein the material of the heat conducting layer is any one of graphene, graphene composite material and carbon nanotubes, and the thermal conductivity of the heating layer is smaller than that of the heat conducting layer.

10. The heating structure of claim 2, wherein the base plate is a bottom plate of a battery pack tray assembly and/or a top plate of a battery pack upper cover.

11. A battery pack, characterized by comprising a heating structure according to any one of claims 1 to 10.

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