Battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery pack which comprises a box body, a heating element and a separator, the partition piece is partially sunken to form an avoiding part, and the heating piece at least partially penetrates through the avoiding part; the heating piece is provided with a first heating part and a second heating part, in the direction perpendicular to the bottom of the box body, the first heating part is overlapped with at least partial area projection of the battery containing area, and the second heating part is overlapped with at least partial area projection of the avoiding part; the resistance value of the first heating part is larger than that of the second heating part. According to the battery pack provided by the utility model, the area, corresponding to the battery accommodating area, of the heating piece can be normally heated, the area, corresponding to the avoiding part, of the heating piece can generate less heat, the dry burning phenomenon is avoided, and the heating piece can adapt to box bodies with different structures due to the fact that the resistance value of the second heating part is relatively low; therefore, only the area where the battery is located is accurately heated, and the heat of the non-battery area and the area which does not need to be heated is reduced as much as possible.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery pack. Background Art

[0002] The battery needs to be within a certain temperature range to ensure good charging and discharging performance. When the battery is in a low temperature environment, it is often necessary to heat the battery to ensure that the battery has a suitable operating temperature.

[0003] In the related art, the battery is heated by sticking a heating film on the side of the battery, but the heating film is glued to the side of the battery and there is a risk of it falling off under vibration conditions for a long time. If the heating film is laid on the bottom of the battery box, although there is no risk of it falling off, since there are often crossbeams in the battery box, the heating film needs to pass through the crossbeams. If the crossbeams are not in contact with the heating film, the area where the heating film passes through the crossbeams is prone to dry burning, and there is a risk of the heating film burning. Utility Model Content

[0004] In view of this, the utility model provides a battery pack to solve the problem that the area where the heating film passes through the beam is prone to dry burning.

[0005] The utility model provides a battery pack, comprising:

[0006] Box;

[0007] The heating element is laid on the bottom of the box;

[0008] A separator is disposed in the box body to separate the box body into at least two battery accommodating areas; the separator is partially recessed to form an escape portion, and the heating element is at least partially disposed through the escape portion;

[0009] The heating element has a first heating portion and a second heating portion, and in a direction perpendicular to the bottom of the box, the first heating portion overlaps with at least a portion of the battery receiving area, and the second heating portion overlaps with at least a portion of the avoidance portion;

[0010] The resistance value of the first heating part is greater than the resistance value of the second heating part.

[0011] Beneficial effect: The battery pack provided by the embodiment of the utility model lays the heating element at the bottom of the box. Due to the support of the bottom of the box, there is no risk of the heating element falling off due to being in a vibrating condition for a long time. At the same time, by making the side of the heating element close to the bottom of the box contact with the bottom of the box, the bottom of the box can help the heating element dissipate heat and prevent heat accumulation. The heating element has a first heating part and a second heating part. In the direction perpendicular to the bottom of the box, the projection of the first heating part overlaps with at least part of the battery accommodating area, and the projection of the second heating part overlaps with at least part of the avoidance part. The resistance value of the first heating part is greater than the resistance value of the second heating part, so that the area corresponding to the heating element and the battery accommodating area can be heated normally, and the area corresponding to the heating element and the avoidance part can heat less, avoiding dry burning. Since the resistance value of the second heating part is low, the heating element can be more adaptable to box components of different structures, so that only the area where the battery is located can be accurately heated, while the non-battery area and the area that does not need to be heated can reduce the heat as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 A schematic diagram of a battery pack of the utility model;

[0014] Figure 2 This is an exploded schematic diagram of the battery pack of the utility model;

[0015] Figure 3 A top view of the battery pack of the utility model;

[0016] Figure 4 for Figure 3 Schematic diagram of the AA section;

[0017] Figure 5 for Figure 4 Enlarged view of point B in the middle;

[0018] Figure 6 It is a cross-sectional view of the heating element of the utility model;

[0019] Figure 7 It is a top view of the heating element of the utility model;

[0020] Figure 8 This is a schematic diagram of the installation of the heating element of the utility model in the box;

[0021] Fig. 9 It is a top view of the matching state of the single battery and the heating element.

[0022] Description of reference numerals:

[0023] 1. Box body; 11. Partition piece; 111. Avoidance part; 112. Leg part; 113. Main body;

[0024] 2. Heating element; 21. First heating part; 211. First heating wire; 22. Second heating part; 221. Second heating wire; 23. Connecting wire;

[0025] 3. Bottom plate; 4. Single battery; 5. Heat exchange plate; 100. Battery compartment; 101. Battery storage area; 200. Electrical compartment. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0027] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the 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 element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] Combine the following Figures 1 to 9 , describing an embodiment of the utility model.

[0031] According to an embodiment of the utility model, a battery pack is provided, comprising:

[0032] Box 1;

[0033] The heating element 2 is laid on the bottom of the box 1;

[0034] The partition 11 is disposed in the box body 1 to divide the box body 1 into at least two battery accommodating areas 101; the partition 11 is partially recessed to form an escape portion 111, and the heating element 2 is at least partially disposed through the escape portion 111;

[0035] The heating element 2 has a first heating portion 21 and a second heating portion 22. In a direction perpendicular to the bottom of the box body 1, the first heating portion 21 overlaps with at least a portion of the battery receiving area 101, and the second heating portion 22 overlaps with at least a portion of the avoiding portion 111.

[0036] The resistance value of the first heating portion 21 is greater than the resistance value of the second heating portion 22 .

[0037] In the battery pack provided by the embodiment of the utility model, the heating element 2 is laid on the bottom of the box body 1. Due to the support of the bottom of the box body 1, there is no risk of the heating element 2 falling off due to being in a vibration condition for a long time. At the same time, by making the side of the heating element 2 close to the bottom of the box body 1 contact with the bottom of the box body 1, the bottom of the box body 1 can help the heating element 2 dissipate heat and prevent heat accumulation. The heating element 2 has a first heating portion 21 and a second heating portion 22. In a direction perpendicular to the bottom of the box body 1, the projections of the first heating portion 21 and at least a portion of the battery accommodating area 101 overlap, and the projections of the second heating portion 22 and at least a portion of the avoidance portion 111 overlap, and the resistance value of the first heating portion 21 is greater than the resistance value of the second heating portion 22, so that the area corresponding to the heating element 2 and the battery accommodating area 101 can be heated normally, and the area corresponding to the heating element 2 and the avoidance portion 111 can generate less heat to avoid dry burning. Since the resistance value of the second heating portion 22 is low, the heating element 2 can be more adaptable to box components of different structures, so that only the area where the battery is located can be accurately heated, while the heat of non-battery areas and areas that do not need to be heated can be reduced as much as possible.

[0038] In this embodiment, the box body 1 serves as the overall structural bearing part, providing structural support for the single battery 4 in the battery pack. Figure 1As shown, the box body 1 is composed of frame beams around the box body 1, and cross beams and longitudinal beams arranged in the box body 1. The separator 11 in this embodiment can be a cross beam arranged in the box body 1, and the extending direction of the cross beam is perpendicular to the stacking direction of the single battery 4.

[0039] A plurality of single cells 4 are stacked to form a battery column, and a plurality of battery columns are arranged in sequence to form a battery pack, and the battery pack is placed in the box 1 .

[0040] A bottom plate 3 may be specifically provided at the bottom of the box body 1 to support the battery pack, and a heat exchange plate 5 may be provided between the bottom plate 3 and the battery pack, which not only supports the battery pack through the heat exchange plate 5, but also realizes heat exchange of the battery pack through the contact between the heat exchange plate 5 and the battery pack. The heat exchange plate 5 may specifically be a cooling plate.

[0041] When only the bottom plate 3 is provided at the bottom of the box body 1 , the heating element 2 is laid on the bottom plate 3 ; when the bottom plate 3 and the heat exchange plate 5 are provided at the bottom of the box body 1 , the heating element 2 is laid on the heat exchange plate 5 .

[0042] Along the stacking direction of the single cells 4, each heating element 2 is constructed as a whole heating film, so that a whole heating film can simultaneously fit multiple single cells 4 in the stacking direction. A whole heating film shares a set of lead-out terminals, thereby simplifying the wiring. If the heating film is set in blocks, multiple connection terminals need to be led out, which will make the internal wiring of the battery pack complicated. In order to ensure the smooth installation of a whole heating film, the separator 11 is partially recessed to form an avoidance portion 111, so as to facilitate the passage of the heating film. In addition, since the separator 11 does not need to be heated, the resistance value of the second heating portion 22 is set to be low to ensure that the heat generation in non-battery areas and areas that do not need to be heated is minimized to prevent dry burning.

[0043] Combination Figure 7 As shown, the heating element 2 includes a plurality of heating films arranged side by side, and each heating film can be arranged in close contact with one or more battery columns. Figure 7 For example, the area corresponding to the second heating portion 22 is the partition 11, and battery columns are respectively arranged on both sides of the partition 11, that is, the first heating portions 21 on both sides of the second heating portion 22 correspond to a battery column respectively.

[0044] A plurality of heating films arranged side by side are connected in parallel via a connecting line 23 .

[0045] In some embodiments, in combination Figure 5 , Figure 6 As shown, a heating wire is inserted into the heating element 2, and the area where the heating wire is located in the first heating portion 21 is defined as the first heating wire 211, and the area where the heating wire is located in the second heating portion 22 is defined as the second heating wire 221;

[0046] In a plane perpendicular to the extending direction of the heating wire, the cross-sectional area of ​​the first heating wire 211 is greater than the cross-sectional area of ​​the second heating wire 221 .

[0047] Since the heating wire is a resistance wire, the larger the cross-sectional area of ​​the resistance wire, the smaller the resistance, and the smaller the heat generated when the same current flows. By making the cross-sectional area of ​​the first heating wire 211 larger than the cross-sectional area of ​​the second heating wire 221, the heat generated by the second heating portion 22 can be reduced, thereby reducing the heat generated by the area corresponding to the avoidance portion 111 of the second heating portion 22, avoiding dry burning, and increasing the service life of the heating element 2.

[0048] Since the resistance value of the second heating portion 22 is relatively low, the heating element 2 can be more adaptable to box components of different structures, so as to accurately heat only the area where the battery is located, while the heat generation of non-battery areas and areas that do not need to be heated can be reduced as much as possible.

[0049] In this embodiment, the heating wire is formed by etching process, and different widths can be etched for different areas to meet the needs of different cross-sectional areas.

[0050] In this embodiment, the cross section of the first heating wire 211 may be rectangular, and the cross section of the second heating wire 221 may also be rectangular.

[0051] In some embodiments, in a plane perpendicular to the heating element 2 , the thickness of the first heating wire 211 and the thickness of the second heating wire 221 are both M, and satisfy: 0.05 mm ≤ M ≤ 0.15 mm.

[0052] As an optional implementation form, the thickness M of the first heating wire 211 and the thickness M of the second heating wire 221 can be 0.05 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, etc.

[0053] In some embodiments, along the extension direction of the separator 11 , the width of the first heating wire 211 is N1, and satisfies: 2 mm ≤ N1 ≤ 4 mm;

[0054] Along the extending direction of the separator 11 , the width of the second heating wire 221 is N2 and satisfies: 6 mm ≤ N2 ≤ 50 mm.

[0055] As an optional implementation form, the width N1 of the first heating wire 211 along the extending direction of the separator 11 can be 2 mm, 2.2 mm, 2.3 mm, 2.5 mm, 2.8 mm, 3 mm, 3.2 mm, 3.5 mm, 4 mm, etc.

[0056] As an optional implementation form, the width N2 of the second heating wire 221 along the extension direction of the partition 11 can be 6 mm, 7 mm, 8 mm, 10 mm, 15 mm, 20 mm, 25 mm, 35 mm, 40 mm, 45 mm, 48 mm, 50 mm, etc.

[0057] As a variation, the cross-section of the first heating wire 211 may also be an ellipse or a racetrack shape, and similarly, the cross-section of the second heating wire 221 may also be an ellipse or a racetrack shape, and similarly.

[0058] In order to accurately calculate the heat generated by the first heating part 21 and the second heating part 22, it is necessary to measure the resistance values ​​of the first heating part 21 and the second heating part 22. The specific measurement method is as follows:

[0059] Step 1: Take a complete heating film, which must include a first heating portion 21 and a second heating portion 22;

[0060] Step 2: Obtain the length data of the first heating portion 21 in the design requirements, and use a length measuring tool to measure the required length of the first heating portion 21 in the heating film of step 1. The length measuring tool may include a vernier caliper, a ruler, a tape measure, etc.;

[0061] Step 3: Use a cutting tool to cut the required length of the first heating portion 21;

[0062] Step 4: Use a resistance measuring instrument to measure the resistance value of the first heating portion 21 intercepted in step 3, wherein the resistance measuring instrument includes an internal resistance meter, a multimeter, etc.;

[0063] Step 5: Obtain the length data of the second heating portion 22 in the design requirements, and use a length measuring tool to measure the required length of the second heating portion 22 in the heating film of step 1. The length measuring tool may include a vernier caliper, a ruler, a tape measure, etc.;

[0064] Step 6: Use a cutting tool to cut the required length of the second heating portion 22;

[0065] Step 7: Use a resistance measuring instrument to measure the resistance value of the second heating portion 22 intercepted in step 6, wherein the resistance measuring instrument includes an internal resistance meter, a multimeter, etc.

[0066] Thus, the resistance values ​​of the first heating portion 21 and the second heating portion 22 of corresponding lengths are obtained.

[0067] In some embodiments, in combination Figure 4 As shown, the partition 11 includes a main body 113 and a leg portion 112 extending from a local area of ​​the main body 113 toward the bottom of the box body 1, and the leg portion 112 is fixed to the bottom of the box body 1;

[0068] The avoidance portion 111 is formed between two adjacent leg portions 112 .

[0069] Since the frame beams arranged around the box body 1 usually cannot meet the strength requirements of the whole pack, the structural strength of the whole pack can be improved by adding a partition 11 inside the box body 1. However, at the same time, the partition 11 divides the inside of the box body 1 into multiple areas. If the heating element 2 is divided into blocks to correspond to different areas, multiple connection terminals need to be led out, resulting in complicated wiring inside the battery pack. If an opening area for leading out the connection terminal is formed on the partition 11, although it can save space inside the pack, the opening on the partition 11 will affect the strength of the partition 11.

[0070] In this embodiment, the separator 11 is extended from a local area of ​​the main body 113 toward the bottom of the box body 1 to form a leg portion 112, and the avoidance portion 111 is formed between two adjacent leg portions 112, so that the strength of the separator 11 can be avoided by opening a hole in the separator 11. That is, the overall arrangement requirements of the heating element 2 are met, and the complicated wiring inside the battery pack is avoided, and the structural strength of the separator 11 can be guaranteed.

[0071] Combination Figure 3 As shown, one of the crossbeams in the box body 1 divides the box body 1 into a battery compartment 100 and an electrical compartment 200, and the heating element 2 is arranged in the battery compartment 100 and connected to the control unit in the electrical compartment 200 through a connecting line 23. The heating element 2 heats only the battery compartment 100 area.

[0072] In some embodiments, the avoidance portion 111 includes a avoidance hole, and the heating element 2 passes through the avoidance hole.

[0073] In some embodiments, in combination Figure 5 As shown, the extending direction of the heating element 2 is perpendicular to the extending direction of the partition 11;

[0074] Along the extending direction of the partition 11 , the width of the avoidance portion 111 is W, the maximum width of the heating element 2 is D, and the following relation is satisfied: D≤W.

[0075] By making the width of the avoidance portion 111 greater than or equal to the maximum width of the heating element 2, the installation of the heating element 2 can be facilitated after the box body 1 and the partition 11 are assembled, and the heating film can pass through the avoidance portion 111 smoothly to avoid interference from the avoidance portion 111. There is no need to curl or bend the heating film, thereby ensuring the integrity of the heating film and avoiding assembly damage.

[0076] In some embodiments, in combination Figure 5 As shown, in the direction perpendicular to the bottom of the box body 1, the height of the avoidance portion 111 is H, and satisfies: 0.05mm≤H≤30mm.

[0077] By limiting the lower limit of the height of the avoidance portion 111, it can be ensured that the avoidance portion 111 reserves a suitable height for the heating element 2 to pass through; by limiting the upper limit of the height of the avoidance portion 111, it can be prevented that the opening of the avoidance portion 111 is too large to affect the structural strength of the partition 11.

[0078] In some embodiments, in combination Fig. 9 As shown, the battery pack further includes a plurality of single cells 4, and the plurality of single cells 4 are stacked to form a battery column;

[0079] The heating element 2 is disposed between the battery array and the bottom of the box 1;

[0080] The stacking direction of the battery array is parallel to the extension direction of the heating element 2 , and the length direction of the single battery 4 is perpendicular to the extension direction of the heating element 2 ; in the length direction of the single battery 4 , the heating element 2 at least fits the middle area of ​​the battery array.

[0081] By making the heating element 2 fit at least with the middle area of ​​the battery array, it is possible to ensure that the heating element 2 heats the battery array uniformly, thereby increasing the service life of the single battery 4 .

[0082] In some embodiments, the heating element 2 and the single battery 4 are fixed by gluing, thereby ensuring the close fit between the heating element 2 and the single battery 4 and the effect of heat transfer. The glue used to bond the heating element 2 and the single battery 4 can be a thermally conductive glue.

[0083] Obviously, the above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. Although the embodiments of the present utility model are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present utility model, and such modifications and variations are all within the scope defined by the present utility model.

Claims

1. A battery pack, characterized in that: include: Box body (1); A heating element (2) is laid on the bottom of the box (1); A separator (11) is arranged in the box (1) to separate the box (1) into at least two battery accommodating areas (101); the separator (11) is partially recessed to form an escape portion (111), and the heating element (2) is at least partially disposed through the escape portion (111); The heating element (2) comprises a first heating portion (21) and a second heating portion (22); in a direction perpendicular to the bottom of the box (1), the projection of the first heating portion (21) overlaps with at least a portion of the battery containing area (101), and the projection of the second heating portion (22) overlaps with at least a portion of the avoiding portion (111); The resistance value of the first heating part (21) is greater than the resistance value of the second heating part (22).

2. The battery pack according to claim 1, characterized in that: A heating wire is inserted into the heating element (2), and the area where the heating wire is located in the first heating portion (21) is defined as the first heating wire (211), and the area where the heating wire is located in the second heating portion (22) is defined as the second heating wire (221); In a plane perpendicular to the extension direction of the heating wire, the cross-sectional area of ​​the first heating wire (211) is greater than the cross-sectional area of ​​the second heating wire (221).

3. The battery pack according to claim 2, characterized in that: In a plane perpendicular to the heating element (2), the thickness of the first heating wire (211) and the thickness of the second heating wire (221) are both M, and satisfy the following relationship: 0.05 mm ≤ M ≤ 0.15 mm.

4. The battery pack according to claim 3, characterized in that: Along the extension direction of the separator (11), the width of the first heating wire (211) is N1, and satisfies: 2mm≤N1≤4mm; Along the extension direction of the separator (11), the width of the second heating wire (221) is N2, and satisfies: 6mm≤N2≤50mm.

5. The battery pack according to claim 1, characterized in that: The partition (11) comprises a main body (113) and a leg portion (112) extending from a local area of ​​the main body (113) toward the bottom of the box (1), and the leg portion (112) is fixed to the bottom of the box (1); The avoidance portion (111) is formed between two adjacent leg portions (112).

6. The battery pack according to claim 5, characterized in that: The avoidance portion (111) comprises an avoidance hole, and the heating element (2) passes through the avoidance hole.

7. The battery pack according to claim 5, characterized in that: The extending direction of the heating element (2) is perpendicular to the extending direction of the partition (11); Along the extension direction of the partition (11), the width of the avoidance portion (111) is W, the maximum width of the heating element (2) is D, and the following condition is satisfied: D≤W.

8. The battery pack according to claim 5, characterized in that: In a direction perpendicular to the bottom of the box body (1), the height of the avoidance portion (111) is H, and satisfies: 0.05 mm ≤ H ≤ 30 mm.

9. The battery pack according to any one of claims 1 to 8, characterized in that: The battery pack further comprises a plurality of single cells (4), wherein the plurality of single cells (4) are stacked to form a battery column; The heating element (2) is arranged between the battery array and the bottom of the box (1); The stacking direction of the battery array is parallel to the extension direction of the heating element (2), and the length direction of the single battery (4) is perpendicular to the extension direction of the heating element (2); in the length direction of the single battery (4), the heating element (2) is at least in contact with the middle area of ​​the battery array.

10. The battery pack according to claim 9, characterized in that: The heating element (2) and the single battery (4) are fixed by gluing.

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