Heating sheet and battery pack

Abstract

The utility model relates to a heating sheet and a battery pack, and belongs to the technical field of heating sheets, the heating sheet comprises an insulating layer and a heating circuit embedded in the insulating layer, the heating circuit comprises at least two confluence heating wires and at least two branch heating wires connecting the adjacent confluence heating wires in series, the branch heating wires located between the adjacent confluence heating wires are arranged in parallel. According to the heating circuit, the adjacent confluence heating wires are arranged in series and are matched with the branch heating wires which are arranged between the adjacent confluence heating wires in parallel, so that the heating circuit which is arranged in series and in parallel is formed, and if a certain branch heating wire is short-circuited due to overcurrent or external collision and the like, the other branch heating wires can also conduct the confluence heating wires; the heating plate can be used in emergency, buffer time for replacement is reserved for personnel, the risk of complete failure of the heating plate due to open circuit is reduced, and the practicability of the heating plate is improved.

Description

Technical Field

[0001] The present application relates to the technical field of heating sheets, and in particular to a heating sheet and a battery pack. Background Art

[0002] Currently, lithium-ion batteries have been widely used in power battery systems or household energy storage systems. However, in low-temperature environments, the battery's charge and discharge performance is greatly limited. In order to improve the charge and discharge performance of lithium-ion batteries in low-temperature environments, they need to be heated. Currently, the commonly used heating methods on the market include water heater heating, PTC heating sheet heating, silicone heating sheet heating, and polyimide heating sheet heating.

[0003] In the related technology, the patent with authorization announcement number CN217740644U discloses a heating plate and a battery module, in which the heating circuit on the heating plate is an integrally formed series circuit. If the heating circuit is broken due to overcurrent or external collision, the heating plate will completely lose its heating function and cannot be used in an emergency. At the same time, the expansion holes on the heating plate that are opened at the distribution position of the heating circuit are too long, which can easily lead to installation misalignment or wrinkles on the heating plate.

[0004] Therefore, it is necessary to study and improve the above structure and provide a heating plate and a battery pack in order to achieve a more practical purpose. Utility Model Content

[0005] In response to the shortcomings or one of the shortcomings of the above-mentioned background technology, the embodiments of the present application provide a heating plate and a battery pack, wherein the heating circuits on the heating plate are arranged in a mixed series-parallel manner, thereby reducing the risk of complete failure of the heating plate due to short circuit and improving the practicality of the heating plate.

[0006] In a first aspect, an embodiment of the present application provides a heating sheet, comprising:

[0007] An insulating layer and a heating circuit embedded in the insulating layer, wherein the heating circuit comprises at least two sections of converging heating wires and at least two sections of branch heating wires connecting adjacent converging heating wires in series, and the branch heating wires between adjacent converging heating wires are arranged in parallel.

[0008] In some embodiments, the branch heating wires are symmetrically distributed on both sides of the converging heating wire, and the branch heating wires include two continuous U-shaped bending sections that are interconnected and symmetrically distributed.

[0009] In some embodiments, the continuous U-shaped bending section has a plurality of transverse heating sections parallel to the converging heating wire and a plurality of longitudinal heating sections perpendicular to the converging heating wire.

[0010] In some embodiments, the length of the transverse heating segment is greater than the length of the longitudinal heating segment, and a plurality of the transverse heating segments are distributed at equal intervals along a direction perpendicular to the converging heating wire.

[0011] In some embodiments, the cross section of each of the transverse heating segments is constant along its length direction, and the cross sections of the plurality of transverse heating segments gradually decrease in a direction away from the converging heating wire.

[0012] In some embodiments, the heating plate further includes a thermally conductive adhesive layer disposed on a surface of one side of the insulating layer, and a thermal insulation layer disposed on a surface of the other side of the insulating layer.

[0013] In some embodiments, the heating plate is provided with expansion holes on both sides of the converging heating wire, and the cross-section of the expansion holes is a rounded rectangle.

[0014] In some embodiments, the number of the heating plates is two and they are connected in series via a first wire, and one end of the heating plate away from the first wire is electrically connected to a terminal via a second wire.

[0015] In some embodiments, the ends of the first wire and the second wire are both provided with insulating protective ears adhered to the outer surface of the heating plate.

[0016] In a second aspect, an embodiment of the present application provides a battery pack, including:

[0017] The heating plate described in any one of the above items.

[0018] The beneficial effects of the technical solution provided by this application include:

[0019] An embodiment of the present application provides a heating plate and a battery pack. Due to the insulating layer and the heating circuit embedded in the insulating layer, the heating circuit includes at least two sections of convergent heating wires and at least two sections of branch heating wires that connect adjacent convergent heating wires in series, and the branch heating wires located between adjacent convergent heating wires are arranged in parallel.

[0020] Therefore, if a branch heating wire is short-circuited due to overcurrent or external collision, the other branch heating wires can still conduct the convergent heating wire, which will not cause the heating plate to completely lose its heating function. It can be used in an emergency, leaving buffer time for personnel to replace it, thereby reducing the risk of the heating plate completely failing due to a short circuit and improving the practicality of the heating plate. The heating power of the branch heating wires arranged in parallel between two adjacent convergent heating wires can be designed separately according to the heating needs, and can be equal or unequal to meet the different heating power requirements of the upper and lower ends of the battery cell, so as to further improve the practicality of the heating plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 A schematic diagram of the heating circuit structure provided in an embodiment of the present application;

[0023] Figure 2 A schematic diagram of the structure of the heating plate provided in the embodiment of the present application;

[0024] Figure 3 This is a schematic diagram of the implementation of the heating plate provided in the embodiment of the present application.

[0025] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0026] 1. Heating plate; 2. Insulating layer; 3. Heating circuit; 31. Converging heating wire; 32. Branching heating wire; 321. Continuous U-shaped bending section; 3211. Horizontal heating section; 3212. Longitudinal heating section; 4. Thermal conductive adhesive layer; 5. Insulating layer; 6. Expansion hole; 7. First conductor; 8. Second conductor; 9. Terminal; 10. Insulating protection ear. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0028] In response to the shortcomings or one of the shortcomings of the above-mentioned background technology, the embodiments of the present application provide a heating plate and a battery pack, wherein the heating circuits on the heating plate are arranged in a mixed series-parallel manner, thereby reducing the risk of complete failure of the heating plate due to short circuit and improving the practicality of the heating plate.

[0029] See also Figures 1 to 3 As shown, the first aspect of the embodiment of the present application provides a heating sheet, comprising:

[0030] The insulating layer 2 and the heating circuit 3 embedded in the insulating layer 2, the heating circuit 3 includes at least two sections of convergent heating wires 31, and at least two sections of branch heating wires 32 connecting adjacent convergent heating wires 31 in series, and the branch heating wires 32 located between adjacent convergent heating wires 31 are arranged in parallel.

[0031] The heating circuit 3 on the heating plate 1 of the embodiment of the present application is entirely covered with an insulating layer 2, so that it is convenient to attach it to the battery cell of the battery pack for heating, wherein the heating circuit 3 includes at least two sections of converging heating wires 31, and at least two sections of branch heating wires 32 that connect adjacent converging heating wires 31 in series, and the branch heating wires 32 are arranged in parallel. If the branch heating wire 32 is short-circuited due to overcurrent or external collision, the other branch heating wires 32 can still conduct the converging heating wire 31, and thus the heating plate 1 will not completely lose its heating effect. It can be used in an emergency, leaving buffer time for personnel to replace it, thereby reducing the risk of complete failure of the heating plate 1 due to a short circuit, and improving the practicality of the heating plate 1.

[0032] For example, in this embodiment, the heating circuit 3 is formed in an integral manner, and the number of the converging heating wires 31 is multiple sections, which are intermittently distributed along the length direction of the heating plate 1 and are located on the bisector of the width direction of the heating plate 1. Two adjacent sections of the converging heating wires 31 are connected by two sections of branch heating wires 32 arranged in parallel. The two sections of branch heating wires 32 arranged in parallel form a single heating operation part for the battery cell. Multiple sections of the converging heating wires 31 are arranged in series, which cooperate with the parallel arrangement of the branch heating wires 32 to form a mixed series-parallel arrangement.

[0033] The heating power of the branch heating wires 32 arranged in parallel between two adjacent sections of the converging heating wires 31 can be designed separately according to the heating needs, and can be equal or unequal, so as to meet the different heating power requirements of the upper and lower ends of the battery cell. In addition, since the converging heating wires 31 are distributed on the bisectors in the width direction of the heating sheet 1, the expansion holes 6 opened between the adjacent branch heating wires 32 are interrupted by the converging heating wires 31 to form intermittent expansion holes 6, which can reduce the risk of installation misalignment or wrinkles on the heating sheet 1 caused by the expansion holes 6 being too long.

[0034] In some alternative embodiments: See Figures 1 to 3 As shown, an embodiment of the present application provides a heating plate, wherein the branch heating wires 32 of the heating plate 1 are symmetrically distributed on both sides of the converging heating wire 31, and the branch heating wires 32 include two continuous U-shaped bending sections 321 that are interconnected and symmetrically distributed.

[0035] The branch heating wires 32 of the heating plate 1 of the embodiment of the present application are symmetrically distributed on both sides of the converging heating wire 31 to form a single heating operation part for the battery cell. The branch heating wires 32 include symmetrically distributed continuous U-shaped bending sections 321, which are convenient for uniform distribution in the insulating layer 2 to improve the power density.

[0036] Specifically, two adjacent sections of the convergent heating wire 31 are connected by two symmetrically distributed branch heating wires 32. The heating area covered by the branch heating wires 32 is rectangular. The branch heating wires 32 include two continuous U-shaped bending sections 321 that are interconnected and symmetrically distributed. The extension direction of the U-shaped bending section is perpendicular to the convergent heating wire 31, thereby forming a uniform distribution, effectively improving the power density.

[0037] In some alternative embodiments: See Figures 1 to 3 As shown, an embodiment of the present application provides a heating plate, wherein the continuous U-shaped bending section 321 of the heating plate 1 has a plurality of transverse heating sections 3211 parallel to the converging heating wire 31 and a plurality of longitudinal heating sections 3212 perpendicular to the converging heating wire 31 .

[0038] The continuous U-shaped bending section 321 on the branch heating wire 32 of the heating plate 1 of the embodiment of the present application includes a plurality of transverse heating sections 3211 and a plurality of longitudinal heating sections 3212. The plurality of transverse heating sections 3211 have the same length and are parallel to the converging heating wire 31. At the same time, they are evenly spaced apart in a direction away from the converging heating wire 31. A longitudinal heating section 3212 is integrally connected between two adjacent transverse heating sections 3211. The transverse heating sections 3211 ensure the heating coverage area of ​​the battery cell, thereby effectively improving the power density.

[0039] In some alternative embodiments: See Figures 1 to 3 As shown, an embodiment of the present application provides a heating plate, in which the length of the transverse heating section 3211 of the heating plate 1 is greater than the length of the longitudinal heating section 3212, and multiple transverse heating sections 3211 are evenly spaced along a direction perpendicular to the convergent heating wire 31.

[0040] The length of the transverse heating segment 3211 on the branch heating wire 32 of the heating plate 1 of the embodiment of the present application is much longer than the length of the longitudinal heating segment 3212. The transverse heating segment 3211 is mainly used to ensure the heating coverage area of ​​the battery cell. At the same time, in order to ensure the heating effect of the heating plate 1, the transverse heating segments 3211 are evenly spaced along the direction perpendicular to the convergent heating wire 31, and the spacing is set to be relatively small.

[0041] In some alternative embodiments: See Figures 1 to 3 As shown, an embodiment of the present application provides a heating plate, the cross-section of each transverse heating segment 3211 of the heating plate 1 is constant along its length direction, and the cross-sections of the multiple transverse heating segments 3211 gradually decrease in the direction away from the convergent heating wire 31.

[0042] The cross-section of each transverse heating segment 3211 on the branch heating wire 32 of the heating plate 1 of the embodiment of the present application is constant along its length direction, but the cross-section of the transverse heating segment 3211 that is farther away from the converging heating wire 31 is smaller, so that the heating power of the heating plate 1 in the width direction gradually increases from the middle to both sides, which can compensate for the temperature difference between the edge of the heating surface and the middle part of the heating surface due to heat dissipation to the outside, thereby achieving consistency in the heating temperature rise of the battery.

[0043] Illustratively, in this embodiment, the converging heating wire 31 and the branch heating wire 32 both adopt sheet heating wires of the same thickness and are integrally formed, that is, the thickness of each transverse heating segment 3211 on the branch heating wire 32 is the same, and the width of the transverse heating segment 3211 that is farther away from the converging heating wire 31 is smaller, and the resistance of the transverse heating segment 3211 with a smaller width is greater, and the resistance is inversely proportional to the heating power. In this way, the heating power of the heating sheet 1 in the width direction gradually increases from the middle to both sides, thereby compensating for the temperature difference between the edge of the heating surface and the middle part of the heating surface due to heat dissipation to the outside, thereby achieving consistency in the heating temperature rise of the battery.

[0044] In some alternative embodiments: See Figures 1 to 3 As shown, an embodiment of the present application provides a heating plate, which further includes a thermally conductive adhesive layer 4 disposed on one surface of the insulating layer 2 and a thermal insulation layer 5 disposed on the other surface of the insulating layer 2 .

[0045] The insulating layer 2 of the heating sheet 1 of the embodiment of the present application is connected to a heat-conducting adhesive layer 4 on one side thereof, and the heat-conducting adhesive layer 4 is used to adhere and fix the heating sheet 1 to the side of the battery cell in the battery pack to be heated. For example, the heat-conducting adhesive layer 4 can be a double-sided adhesive.

[0046] At the same time, the surface of one side of the insulating layer 2 of the heating plate 1 of the embodiment of the present application is connected with an insulating layer 5. The insulating layer 5 can prevent the heat of the heating plate 1 from diffusing outward as much as possible, reduce the radiation heat exchange of the heating plate 1 to the outside world, and achieve the same heating effect as the heating plate 1 without adding the insulating layer 5 while using less energy consumption.

[0047] In some alternative embodiments: See Figures 1 to 3 As shown, an embodiment of the present application provides a heating plate, and the heating plate 1 is provided with expansion holes 6 located on both sides of the converging heating wire 31, and the cross-section of the expansion hole 6 is a rounded rectangle.

[0048] The heating plate 1 of the embodiment of the present application is provided with an expansion hole 6, which can effectively improve the phenomenon that the heating plate 1 expands and deforms when heated, further improve safety, and extend the service life of the heating plate 1. The cross section of the expansion hole 6 is a rounded rectangle, which can prevent the edge of the expansion hole 6 from cracking due to stress concentration.

[0049] At the same time, the expansion holes 6 in this embodiment are distributed on both sides of the convergent heating wire 31, and the expansion holes 6 are interrupted by the convergent heating wire 31 to form intermittent expansion holes 6, which can reduce the risk of installation misalignment or wrinkles on the heating plate 1 caused by the expansion holes 6 being too long.

[0050] In some alternative embodiments: See Figures 1 to 3 As shown, an embodiment of the present application provides a heating plate, wherein the number of the heating plates 1 is two and they are connected in series through a first wire 7 , and one end of the heating plate 1 away from the first wire 7 is electrically connected to a terminal 9 through a second wire 8 .

[0051] There are two heating plates 1 in the embodiment of the present application and they are connected in series through a first wire 7. The two heating plates 1 can be conveniently attached to both sides of the battery cell in the battery pack to be heated. At the same time, one end of the heating plate 1 away from the first wire 7 is electrically connected to a terminal 9 through a second wire 8. The terminal 9 is convenient for connecting to a power source.

[0052] In some alternative embodiments: See Figures 1 to 3 As shown, an embodiment of the present application provides a heating plate, and the ends of the first wire 7 and the second wire 8 of the heating plate 1 are both provided with insulating protective ears 10 adhered to the outer surface of the heating plate 1.

[0053] The ends of the first wire 7 and the second wire 8 of the heating plate 1 of the embodiment of the present application are provided with insulating protective ears 10 adhered to the outer surface of the heating plate 1. After the first wire 7 and the second wire 8 are welded to the internal heating circuit 3 of the heating plate 1, they will pass through the heating plate 1. Adhering the insulating protective ears 10 at the connection between the wire and the heating plate 1 can effectively protect the above-mentioned connection and avoid the phenomenon of the wire falling off and disconnecting the power supply during use.

[0054] At the same time, the converging heating wire of this embodiment is arranged on the bisector of the width direction of the heating plate 1, so that the lead wire of the heating plate 1 can be set in the middle position, which is convenient for setting the insulating protection ear 10 and can reduce the risk of the lead wire falling off to a certain extent.

[0055] See also Figures 1 to 3 As shown, the second aspect of the embodiment of the present application provides a battery pack, including:

[0056] The heating sheet 1 according to any one of the above embodiments.

[0057] The battery pack of the embodiment of the present application uses the heating sheet 1 of any of the above-mentioned embodiments. When the heating sheet 1 is in the working state, the heating sheet 1 is arranged around the battery pack and makes the heating sheet 1 fit the side of the battery cell in the battery pack to be heated. The terminal 9 is connected to the external power supply. The external power supply connected to the terminal 9 is used to supply power to the heating circuit 3 to generate heat and heat the battery cell.

[0058] The heating plate 1 used in the battery pack of the embodiment of the present application gradually increases the heating power from the middle to both sides along the width to compensate for the heat loss caused by the heat exchange between the battery and the two sides of the heating plate 1 in the width direction, so as to achieve uniform temperature rise inside the battery cell. At the same time, the insulation layer 5 on the heating plate 1 reduces the radiation heat exchange of the heating plate 1 to the outside world, so as to achieve the same heating effect as the heating plate 1 without the insulation layer 5 while using less energy consumption. This makes the battery pack using the heating plate 1 have a high industrial competitive advantage and higher industrial utilization value.

[0059] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0060] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0061] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A heating sheet, characterized in that: include: An insulating layer (2) and a heating circuit (3) embedded in the insulating layer (2), the heating circuit (3) comprising at least two sections of converging heating wires (31) and at least two sections of branch heating wires (32) connecting adjacent converging heating wires (31) in series, the branch heating wires (32) located between adjacent converging heating wires (31) being arranged in parallel.

2. The heating sheet according to claim 1, characterized in that: The branch heating wires (32) are symmetrically distributed on both sides of the converging heating wire (31), and the branch heating wire (32) comprises two continuous U-shaped bending sections (321) that are connected to each other and are symmetrically distributed.

3. The heating sheet according to claim 2, characterized in that: The continuous U-shaped bending section (321) has a plurality of transverse heating sections (3211) parallel to the converging heating wire (31) and a plurality of longitudinal heating sections (3212) perpendicular to the converging heating wire (31).

4. The heating sheet according to claim 3, characterized in that: The length of the transverse heating section (3211) is greater than the length of the longitudinal heating section (3212), and the plurality of transverse heating sections (3211) are distributed at equal intervals along a direction perpendicular to the converging heating wire (31).

5. The heating sheet according to claim 3, characterized in that: The cross section of each transverse heating section (3211) remains constant along its length direction, and the cross sections of the plurality of transverse heating sections (3211) gradually decrease in a direction away from the converging heating wire (31).

6. The heating sheet according to claim 1, characterized in that: The heating plate (1) further comprises a heat-conducting adhesive layer (4) arranged on the surface of one side of the insulating layer (2), and a heat-insulating layer (5) arranged on the surface of the other side of the insulating layer (2).

7. The heating sheet according to claim 1, characterized in that: The heating plate (1) is provided with expansion holes (6) located on both sides of the converging heating wire (31), and the cross section of the expansion holes (6) is a rounded rectangle.

8. The heating sheet according to claim 1, characterized in that: The number of the heating plates (1) is two and they are connected in series via a first wire (7); one end of the heating plate (1) away from the first wire (7) is electrically connected to a terminal (9) via a second wire (8).

9. The heating sheet according to claim 8, characterized in that: The ends of the first wire (7) and the second wire (8) are both provided with insulating protective ears (10) adhered to the outer surface of the heating plate (1).

10. A battery pack, characterized in that: include: The heating sheet according to any one of claims 1 to 9.

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