Battery pack and electrical device

Abstract

The present application belongs to the technical field of batteries and provides a battery pack and an electrical device. In the battery pack, an insulating film is provided with an opening area to which a corresponding part of the outer wall of a battery is exposed, and a heat dissipation part is provided in the opening area and is arranged between the outer wall and the inner wall of a frame, so that heat of the battery can be dissipated outwards from the opening area and the heat dissipation part, thereby effectively reducing the thermal runaway risk of the battery. Moreover, the heat dissipation part spaces the outer wall of the battery from the inner wall of the frame, effectively avoiding insulation failure. In addition, because the area S of the opening area of the insulating film, the thickness H of the insulating film and the volume V of the battery satisfy 0.0001≤S×H / V≤0.5, the space of the opening of the insulating film can meet the heat dissipation requirement of the battery, thereby improving the heat dissipation efficiency of the battery and ensuring the safety of the battery pack.

Description

Battery packs and electrical equipment

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on June 26, 2023, with application number 202310766571.5 and application name “Battery Pack and Electrical Equipment”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of battery technology, and specifically relates to a battery pack and electrical equipment. Background Art

[0003] Cell to Pack (CTP) technology can improve space utilization by reducing or eliminating the module structure and placing the batteries directly inside the battery case. Battery cases are typically made of metal. To prevent short circuits caused by contact between the case and the case or other components, an insulating film is typically applied to the battery's periphery to improve insulation. However, the insulating film has poor thermal conductivity, hindering heat dissipation and making thermal runaway more likely.

[0004] Application Contents

[0005] An embodiment of the present application provides a battery pack, aiming to overcome the technical problem that the insulating film of the battery in the existing battery pack has poor thermal conductivity, is not conducive to the heat dissipation of the battery, and is prone to thermal runaway; another purpose of the embodiment of the present application is to provide an electrical device.

[0006] In a first aspect, a battery pack according to an embodiment of the present application includes:

[0007] A frame having a plurality of inner walls, wherein the plurality of inner walls enclose a receiving space;

[0008] a battery, disposed in the accommodation space, the battery having a plurality of outer walls;

[0009] an insulating film covering the plurality of outer walls, the insulating film being provided with an opening area opposite to the outer walls, the opening area being configured to expose at least a portion of the outer walls from the insulating film;

[0010] a heat dissipation portion, at least a portion of which is disposed in the opening area and between the outer wall and the inner wall;

[0011] The area of ​​the opening is S mm. 2 , the thickness of the insulating film is H mm, and the volume of the battery is V mm 3 , the battery pack satisfies the following relationship: 0.0001≤S×H / V≤0.5.

[0012] In some embodiments, the battery pack satisfies the following relationship: 0.001≤S×H / V≤0.2.

[0013] In some embodiments, the heat dissipation portion is in contact with the inner wall, and the volume of the heat dissipation portion is V1mm 3 , the battery pack satisfies the following relationship: V1 / (S×H)≥1.

[0014] In some embodiments, the outer wall is rectangular, the length of the outer wall is L mm, the width of the outer wall is M mm, the maximum dimension of the opening area in the length direction relative to the outer wall is L1 mm, and the maximum dimension of the opening area in the width direction relative to the outer wall is M1 mm, and the battery pack satisfies the following relationship: 0.01≤L1 / L<1; and / or, 0.01≤M1 / M<1.

[0015] In some embodiments, the battery pack satisfies the following relationship: L1 / L≥0.5; and / or, M1 / M≥0.5.

[0016] In some embodiments, the thickness of the heat dissipation portion is H1 mm, and the battery pack satisfies the following relationship: H1 / H≥1.

[0017] In some embodiments, the plurality of outer walls include a top wall, a bottom wall, and a plurality of side walls connected between the top wall and the bottom wall;

[0018] The portion of the insulating film covering the bottom wall is provided with the opening area, and / or the portion of the insulating film covering the side wall is provided with the opening area.

[0019] In some embodiments, the insulating film is provided with a plurality of the opening areas;

[0020] The plurality of opening areas include a first opening area and a second opening area provided on the portion of the insulating film covering the bottom wall, and / or the plurality of opening areas include a third opening area and a fourth opening area provided on the portion of the insulating film covering the side wall.

[0021] In some embodiments, the insulating film is provided with a plurality of the opening areas;

[0022] The plurality of opening areas include a first opening area and a second opening area provided on a portion of the bottom wall covered by the insulating film, the first opening area and the second opening area being configured to expose a portion of the bottom wall from the insulating film; the heat dissipation portion includes a first heat dissipation portion and a second heat dissipation portion, the first heat dissipation portion being provided in the first opening area, the second heat dissipation portion being provided in the second opening area, and the first heat dissipation portion and the second heat dissipation portion being provided between the bottom wall and the inner wall;

[0023] And / or, the plurality of opening areas include a third opening area and a fourth opening area provided on the portion of the insulating film covering the side wall, and the third opening area and the fourth opening area are both configured to expose a portion of the side wall from the insulating film; the heat dissipation portion includes a third heat dissipation portion and a fourth heat dissipation portion, the third heat dissipation portion is provided in the third opening area, the fourth heat dissipation portion is provided in the fourth opening area, and the third heat dissipation portion and the fourth heat dissipation portion are provided between the side wall and the inner wall.

[0024] In some embodiments, the frame includes a liquid cooling plate arranged opposite to the bottom wall and / or the side wall, the multiple inner walls include a liquid cooling surface of the liquid cooling plate arranged toward the battery, and the heat dissipation portion is connected between the outer wall and the liquid cooling surface.

[0025] In some embodiments, the plurality of sidewalls include a first sidewall and a second sidewall disposed opposite to each other;

[0026] Portions of the insulating film covering the first side wall and the second side wall are both provided with the opening area.

[0027] In some embodiments, the material of the heat dissipation portion is one or more of phase change material, thermal conductive adhesive, and thermal conductive graphite sheet.

[0028] In a second aspect, an electrical device described in an embodiment of the present application includes the battery pack described in any of the above embodiments. Beneficial effects

[0029] The battery pack of the embodiment of the present application is provided with an opening area on its insulating film, exposing a corresponding part of the outer wall of the battery through the opening area, and providing a heat dissipation portion in the opening area, and the heat dissipation portion is arranged between the outer wall and the inner wall of the frame, so that the heat of the battery can be dissipated outward from the opening area and the heat dissipation portion, thereby effectively reducing the risk of thermal runaway of the battery; at the same time, the heat dissipation portion separates the outer wall of the battery and the inner wall of the frame, effectively avoiding insulation failure; in addition, since the area S of the opening area of ​​the insulating film and the thickness H of the insulating film and the volume V of the battery satisfy 0.0001≤S×H / V≤0.5, the space in the opening area of ​​the insulating film can meet the heat dissipation requirements of the battery, improve the efficiency of battery heat dissipation, and ensure the safety of the battery pack.

[0030] The electrical equipment of the embodiment of the present application may include all the technical features and beneficial effects of the above-mentioned battery pack, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings used in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0032] FIG1 is a schematic diagram of the three-dimensional structure of a battery pack provided in an embodiment of the present application;

[0033] FIG2 is a schematic cross-sectional view of the battery pack along line AA in FIG1 ;

[0034] FIG3 is a schematic diagram of a partially enlarged structure of area B in FIG2 ;

[0035] FIG4 is a schematic diagram of the three-dimensional structure of a battery coated with an insulating film in a battery pack according to an embodiment of the present application;

[0036] FIG5 is a schematic structural diagram of the battery in FIG4 viewed along the X direction;

[0037] FIG6 is a schematic structural diagram of the battery in FIG4 viewed along the Z direction;

[0038] FIG7 is a schematic diagram of the three-dimensional structure of the insulating portion in an embodiment of the present application;

[0039] FIG8 is a schematic diagram of a partially enlarged cross-sectional structure of a battery pack in some embodiments of the present application;

[0040] Reference numerals: 100 - frame; 110 - liquid cooling plate; 120 - side plate; 130 - end plate; 111 - liquid cooling surface; 200 - battery; 210 - outer wall; 211 - side wall; 212 - bottom wall; 300 - insulating film; 400 - opening area; 500 - heat dissipation portion.

[0041] Implementation Methods of the Application

[0042] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only 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 those skilled in the art without making creative efforts are within the scope of protection of this application.

[0043] In the description of this application, it should be understood that the terms "length", "width", "thickness", "upper", "lower", "top", "bottom", "inner", "outer", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting this application. In the description of this application, "plurality" means two or more, and "at least one" means one, two, or more than two, unless otherwise clearly and specifically defined.

[0044] The applicant has noticed that in existing battery packs, the insulating film covering the outer periphery of the battery affects the heat dissipation of the battery, making the battery susceptible to thermal runaway.

[0045] In view of this, an embodiment of the present application provides a battery pack, which reduces the heat dissipation effect of the insulating film on the battery.

[0046] Please refer to Figures 1 and 2 together. Figure 1 illustrates the three-dimensional structure of the battery pack of an embodiment of the present application, and Figure 2 illustrates the cross-sectional structure of the battery pack along line AA in Figure 1. In the embodiment of the present application, the battery pack includes a frame 100, a battery 200, and an insulating film 300 covering the battery 200. The multiple inner walls 140 of the frame 100 form a accommodating space for accommodating the battery 200. One or more batteries 200 are provided in the accommodating space, and the insulating film 300 covers the outer wall 210 of the battery 200.

[0047] Specifically, in some embodiments, the frame 100 can be the entire outer box of the battery pack, and the battery 200 is accommodated in the accommodation space surrounded by multiple inner walls 140 of the box. In some embodiments, the frame 100 can also be a combination of a partial structure of the battery pack box and other structures of the battery pack. For example, it can be surrounded by the end plates 130, side plates 120 and the liquid cooling plate 110 at the bottom of the box, or it can be surrounded by beams (not shown in the figure) and liquid cooling plates 110 provided inside the box. It is understood that in the embodiment of the present application, the frame 100 is a structure composed of multiple components arranged around the periphery of one or more batteries 200 and opposite to the outer wall 210 of the battery 200, and the surface of each component facing the battery 200 is the inner wall 140 of the frame 100.

[0048] Please refer to Figures 3, 4, 5 and 6. Figure 3 shows a local enlarged structure of area B in Figure 2, Figure 4 shows the three-dimensional structure of the battery 200 covered with the insulating film 300, Figure 5 shows the structure of the battery 200 in Figure 4 observed along the X direction, and Figure 6 shows the structure of the battery in Figure 4 observed along the Z direction, wherein Figures 5 and 6 do not show the insulating film 300, and schematically show the shape of the opening area 400 on the corresponding outer wall 210 of the battery 200. In the embodiment of the present application, the insulating film 300 is provided with at least one opening region 400 opposite any outer wall 210 of the battery 200. The opening region 400 is used to expose the insulating film 300 to the portion of the outer wall 210 facing the insulating film 300. In other words, one or more opening regions 400 are provided on the insulating film 300. The opening regions 400 are provided on the portion of the insulating film 300 facing any outer wall 210 of the battery 200 (i.e., the portion of the insulating film 300 attached to the outer wall 210). Through the opening regions 400, the corresponding portion of the outer wall 210 is exposed to the insulating film 300. The battery pack also has a heat dissipation portion 500. The heat dissipation portion 500 is at least partially disposed in the opening region 400 and is disposed between the outer wall 210 and the inner wall 140.

[0049] It should be noted that, in some embodiments, only one opening area 400 may be provided on the insulating film 300, and the opening area 400 may be provided corresponding to a certain outer wall 210 of the battery 200 so that the corresponding portion of the outer wall 210 is exposed; in some embodiments, multiple opening areas 400 may be provided on the insulating film 300, each opening area 400 corresponds to an outer wall 210 of the battery 200, and the corresponding portions of the respective opposite outer walls 210 are exposed to the insulating film 300; in some embodiments, multiple opening areas 400 may be provided on the insulating film 300, and the multiple opening areas 400 correspond to the multiple outer walls 210 of the battery 200, and one or more opening areas 400 are provided corresponding to one outer wall 210, and the opening area 400 exposes the corresponding portion of the outer wall 210 to the insulating film 300; in some embodiments, multiple opening areas 400 may be provided on the insulating film 300, and each opening area 400 corresponds to an outer wall 210 of the battery 200, and the opening areas 400 corresponding to the two adjacent outer walls 210 are connected. Correspondingly, the heat dissipation portion 500 is disposed corresponding to the opening area 400 , and each opening area 400 is provided with a heat dissipation portion 500 .

[0050] In the battery pack of the embodiment of the present application, the area of ​​the opening region 400 is S mm 2 , the thickness of the insulating film 300 is H mm, and the volume of the battery 200 is V mm 3 , the battery pack satisfies the following relationship: 0.0001≤S×H / V≤0.5.

[0051] By forming an opening region 400 in the insulating film 300 to expose the outer wall 210 of the battery 200, the insulating film 300's blocking effect on the battery 200's heat dissipation can be reduced. The opening region 400 provides space for the battery 200 to dissipate heat outward, allowing heat generated by the battery 200 to dissipate outward from the opening region 400 opposite the outer wall 210. By ensuring that the area S of the opening region 400 of the insulating film 300 satisfies the aforementioned relationship with the insulating film's thickness H and the battery's volume V, the space in the opening region 400 of the insulating film 300 can meet the heat dissipation requirements of the battery 200, improving the efficiency of the battery 200's heat dissipation and ensuring the safety of the battery pack. Furthermore, the heat dissipation portion 500 directs heat dissipated from the outer wall 210 of the battery 200 toward the opening region 400, effectively reducing the risk of thermal runaway of the battery 200. Furthermore, the heat dissipation portion 500, which separates the outer wall 210 of the battery 200 from the inner wall 140 of the frame 100, effectively prevents insulation failure caused by the opening region 400.

[0052] It should be noted that in the embodiment of the present application, the value of S×H / V is in the range of 0.0001 to 0.5, that is, the value can be any value among 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, or a range between any two values. When the value of S×H / V is larger, the heat dissipation space is larger relative to the battery 200, which is more conducive to the heat dissipation of the battery 200. When S×H / V>0.5, it means that the opening area 400 on the insulating film 300 is relatively too large, which may affect the insulation performance of the battery 200. Therefore, in the embodiment of the present application, S×H / V is controlled to be ≤0.5. When the value of S×H / V is smaller, the heat dissipation space of the battery 200 is smaller, and the heat dissipation effect is relatively reduced. At the same time, the insulation performance of the battery 200 is better. When S×H / V is less than 0.0001, the heat dissipation space of the battery 200 is too small, and the opening area 400 and the heat dissipation portion 500 do not improve the heat dissipation performance of the battery 200 too much. Therefore, in the embodiment of the present application, S×H / V is controlled to be greater than or equal to 0.0001. Optionally, 0.001≤S×H / V≤0.2 to ensure a balance between heat dissipation and insulation effects and ensure the safety of the battery pack.

[0053] It should also be noted that in the above relationship, the area S of the opening area 400 refers to the total area of ​​one or more opening areas 400 corresponding to any outer wall 210, that is, the total area S of all opening areas 400 corresponding to one outer wall 210 of the battery 200. The area S of the opening area 400 can be measured and calculated using a conventional area measurement method. For example, if the opening area 400 is a regular shape (such as a square, circle, ellipse, or ring), the area measurement method of the corresponding shape can be used for measurement and calculation; if the opening area 400 is an irregular shape, the film method can be used for measurement and calculation. That is, a film of uniform mass is attached to the corresponding portion of the outer wall 210 corresponding to the opening area 400, the film attached to the corresponding portion is removed, and the mass of the film is determined. The quotient of the mass of the removed film and the mass per unit area of ​​the film that has been predetermined is determined as the area S of the measured opening area 400.

[0054] Optionally, the area of ​​the opening region 400 satisfies: 1000≤S≤500000, in mm 2 The thickness of the insulating film 300 satisfies: 0.06≤H≤0.12, in mm; the volume of the battery 200 satisfies: 110000≤V≤5550000, in mm 3 .

[0055] The thickness H of the insulating film 300 can be measured using a measuring tool such as a vernier caliper or a micrometer; the volume V of the battery 200 can be calculated by measuring the length, width, and height of the battery 200 .

[0056] Furthermore, in some embodiments, the heat dissipation portion 500 contacts the inner wall 140, and the volume of the heat dissipation portion 500 is V1mm 3 , the battery pack satisfies the following relationship: V1 / (S×H)≥1.

[0057] That is to say, in this embodiment, V1 changes with the change of S×H, and the relationship between V1 and S×H is V1≥(S×H). Therefore, the volume of the heat dissipation portion 500 is greater than or equal to the volume of the corresponding opening area 400, so that the heat dissipation portion 500 is flush with the insulating film 300 or protrudes outside the insulating film 300, and then contacts the inner wall 140 of the frame 100, which can directly conduct the heat generated by the battery 200 to the frame 100, and take away the heat generated by the battery 200 through the frame 100.

[0058] The volume of the heat dissipation portion 500 can be measured according to the actual structure of the heat dissipation portion 500. For example, when the heat dissipation portion 500 is a regular shape such as a cylinder or a rectangular parallelepiped, the geometric dimensions of the heat dissipation portion 500 can be measured, and then the volume V1mm of the heat dissipation portion 500 can be calculated.3 ; When the heat dissipation portion 500 is of an irregular shape, for example, the heat dissipation portion 500 is formed by solidifying a thermally conductive adhesive, it can be melted by heating, and then placed in a regular container to solidify again before measurement; or for the heat dissipation portion 500 that is of an irregular shape and cannot be melted, it can be measured by the drainage method or other known measurement methods. Those skilled in the art can choose the measurement method according to actual conditions.

[0059] Please refer again to Figures 4, 5, and 6. In some embodiments, the battery 200 is a prismatic battery, and the outer wall 210 of the battery 200 is rectangular. Specifically, the outer wall 210 of the battery 200 can be rectangular or square. The length of the outer wall 210 is L mm, the width of the outer wall 210 is M mm, the maximum dimension of the opening area 400 in the longitudinal direction of the outer wall 210 is L1 mm, and the maximum dimension of the opening area 400 in the width direction of the outer wall 210 is M1 mm. The battery pack satisfies the following relationship: 0.01 ≤ L1 / L < 1; and / or, 0.01 ≤ M1 / M < 1.

[0060] That is, L1 / L can be any value within the range of 0.01 or greater and less than 1. For example, L1 / L can be any value among 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.98, or a range between any two values. Within this range, the smaller L1 / L is, the smaller the proportion of the opening area 400 to the length of the corresponding outer wall 210 is, the smaller the space for heat dissipation is, and the risk of insulation failure is also reduced. The larger L1 / L is, the larger the proportion of the opening area 400 to the length of the corresponding outer wall 210 is, and the larger the space for heat dissipation is. To avoid too small a heat dissipation space, L1 / L should be greater than 0.01. In addition, due to the size limitation of the outer wall 210 and to ensure the insulation effect, L1 / L is less than 1. Optionally, L1 / L ≥ 0.5 to ensure sufficient heat dissipation space.

[0061] Accordingly, M1 / M can be any value within the range of 0.01 or greater and less than 1. For example, M1 / M can be any value among 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, or a range between any two values. Within this range, the smaller the M1 / M, the smaller the proportion of the opening area 400 to the width of the corresponding outer wall 210, the smaller the space for heat dissipation, and the lower the risk of insulation failure. The larger the M1 / M, the larger the proportion of the opening area 400 to the width of the corresponding outer wall 210, and the larger the space for heat dissipation. To avoid too small a heat dissipation space, M1 / M should be greater than 0.01. In addition, due to the size limitation of the outer wall 210, M1 / M is less than 1. Optionally, M1 / M≥0.5 can ensure sufficient heat dissipation space.

[0062] It should be noted that, in the description of this application, generally speaking, the larger side of the outer wall 210 of the battery 200 is the length of the outer wall 210, and the smaller side is the width of the outer wall 210. In some embodiments, for outer walls 210 with equal side dimensions, any side can be taken as the length, and the side perpendicular to the side is the width.

[0063] Specifically, referring to FIG5 , the side wall 211 of the battery 200 has a length in the Z direction of L mm, with the length of the side wall 211 being the Z direction. That is, in the Z direction, the maximum dimension of the opening area 400 corresponding to the side wall 211 is L1 mm. The side wall 211 has a width in the Y direction of M, with the width of the side wall 211 being the Y direction. That is, in the Y direction, the maximum dimension of the opening area 400 corresponding to the side wall 211 is M1 mm. Referring to FIG6 , the bottom wall 212 of the battery 200 has a length in the X direction of L mm, with the length of the bottom wall 212 being the X direction. That is, in the X direction, the maximum dimension of the opening area 400 corresponding to the bottom wall 212 is L1 mm. The bottom wall 212 has a width in the Y direction of M, with the width of the bottom wall 212 being the Y direction. That is, in the Y direction, the maximum dimension of the opening area 400 corresponding to the bottom wall 212 is M1 mm. Among them, L, L1, M1 and M can all be measured by measuring tools such as vernier calipers or micrometers.

[0064] Optionally, the outer wall 210 is rectangular, and its length satisfies: 100≤L≤1000, in mm; the width of the outer wall 210 satisfies: 10≤M≤500, in mm.

[0065] Further, please refer to Figure 7, which illustrates the three-dimensional structure of the heat dissipation portion 500 in an embodiment of the present application. In some embodiments, when the orthographic projection area of ​​the heat dissipation portion 500 on the corresponding outer wall 210 is less than or equal to the orthographic projection area of ​​the opening area 400 on the corresponding outer wall 210, the thickness of the heat dissipation portion 500 is H1 mm, and the battery pack satisfies the following relationship: H1 / H ≥ 1. This allows the heat dissipation portion 500 to be flush with the insulating film 300 or protrude outside the insulating film 300, and then contact the inner wall 140 of the frame 100, so that the heat generated by the battery 200 can be directly transferred to the frame 100, and the heat generated by the battery 200 can be removed by the frame 100. Among them, H1 can be measured using a measuring tool such as a vernier caliper or micrometer. It will be understood that in this embodiment, the thickness of the heat dissipation portion 500 is determined based on the thickness of the insulating film 300, and H1 ≥ H.

[0066] Furthermore, H1≤2mm, 1≤H1 / H≤10 / 3, so that the heat dissipation of the heat dissipation part 500 is more uniform, and the optional 50 / 9≤H1 / H≤25 / 6, so that the thermal conductivity and insulation properties of the battery pack are in a better state, and the cooling effect is obvious.

[0067] It should be noted, referring to Figure 8, that in some embodiments, when the heat dissipation portion 500 is a thermally conductive adhesive, and during the coating process, the thermally conductive adhesive may overflow from the opening area 400, then the coating area of ​​the heat dissipation portion 500 may be larger than the area of ​​the opening area 400, and may even be larger than the area of ​​the corresponding outer wall 210 (see Figure 8). In this case, the thickness of the heat dissipation portion 500 is greater than the thickness of the insulating film 300, and the thickness of the heat dissipation portion 500 is the thickness of the portion whose positive projection is within the opening area 400.

[0068] Please refer to Figures 4, 5 and 6 again. In the embodiment of the present application, the multiple outer walls 210 of the battery 200 include a top wall, a bottom wall 212 and a plurality of side walls 211 connected between the top wall and the bottom wall 212. The portion of the insulating film 300 covering the bottom wall 212 and / or the side wall 211 is provided with an opening area 400. Among them, the top wall is the outer wall of the battery 200 where the pole is set. The top wall can be integrally formed with the side wall 211, or it can be split and covered on the battery shell formed by connecting the bottom wall 212 and the side wall 211. In the embodiment of the present application, the opening area 400 can be opened in the portion of the insulating film 300 opposite to the bottom wall 212 of the battery 200, or it can be opened in the portion of the insulating film 300 opposite to the side wall 211 of the battery 200. When the insulating film 300 is provided with a plurality of opening regions 400, the opening regions 400 may be provided on the portions of the insulating film 300 corresponding to the bottom wall 212 and the side walls 211, or the opening regions 400 may be provided only on the portions corresponding to the plurality of side walls 211. It will be understood that, in the description of this application, the plurality of side walls 211 include the two large surfaces (the largest surfaces of the square battery cell) and the two side surfaces (surfaces connected to the large surfaces) of the square battery.

[0069] Further, in some embodiments, the insulating film 300 is provided with a plurality of opening areas 400, the plurality of opening areas 400 include a first opening area and a second opening area provided on the portion of the insulating film 300 covering the bottom wall 212, and / or, the plurality of opening areas 400 include a third opening area and a fourth opening area provided on the portion of the insulating film 300 covering the side wall 211. That is to say, at least two opening areas 400 can be opened on the part of the insulating film 300 covering the bottom wall 212, namely the first opening area and the second opening area, and the shapes of the first opening area and the second opening area can be the same or different; at least two opening areas 400 can also be opened on the part of the insulating film 300 covering any side wall 211, namely the third opening area and the fourth opening area, and the shapes of the third opening area and the fourth opening area can be the same or different; or, according to needs, the first opening area and the second opening area are set on the part of the insulating film 300 covering the bottom wall 212, and the third opening area and the fourth opening area are set on the part of the insulating film 300 covering the side wall 211, and the shapes of the first opening area, the second opening area, the third opening area and the fourth opening area can be the same or different; the above can be specifically selected according to actual needs.

[0070] In some embodiments, the battery's multiple sidewalls 211 include a first sidewall and a second sidewall disposed opposite each other. The portions of the insulating film 300 covering the first and second sidewalls each have an opening 400. The bottom wall 212 of the battery 200 also has an opening 400. Providing openings 400 on the three outer walls 210 further improves the heat dissipation efficiency of the battery 200 and ensures the safety of the battery pack.

[0071] Further, referring again to Figures 1, 2, and 3, the frame 100 includes a liquid cooling plate 110 disposed opposite the bottom wall 212 and / or the side walls 211. The plurality of inner walls 140 include a liquid cooling surface 111 of the liquid cooling plate 110, which faces the battery 200. The heat dissipation portion 500 is connected between the outer wall 210 and the liquid cooling surface 111. Heat generated by the battery 200 is thereby directed to the liquid cooling surface 111 through the corresponding heat dissipation portion 500 disposed in the opening region 400, where it is removed by the liquid cooling plate 110, thereby improving cooling efficiency and further ensuring the safety of the battery pack.

[0072] In some embodiments, the heat dissipation portion 500 may be shaped like at least one of a square, a circle, and an annular shape; and / or the heat dissipation portion 500 may be made of at least one of a phase change material, a thermally conductive adhesive, and a thermally conductive graphite sheet. In other words, the heat dissipation portion 500 may be shaped like one of a square, a circle, and an annular shape. Alternatively, when multiple opening areas 400 are provided, the heat dissipation portions 500 provided in different opening areas 400 may be shaped like a combination of square, circle, and annular shapes.

[0073] In some embodiments, the material of the heat dissipation portion 500 may be a phase change material, a thermally conductive adhesive, a thermally conductive graphite sheet, or a combination thereof, wherein the phase change material may be a packaged phase change material.

[0074] Furthermore, when the heat dissipation portion 500 is made of phase change material or thermally conductive graphite sheet, the projection shape of the heat dissipation portion 500 on the outer wall 210 corresponding to the opening area 400 is one or more of square, circular, and annular.

[0075] Next, specific embodiments of the battery pack of the present application are provided, and the present application is described in more detail through specific embodiments. It can be seen from the following embodiments that, in actual implementation, when the battery pack satisfies the relationship of the present application, the heat dissipation effect of the battery pack is in an optional state.

[0076] Example 1: The frame 100 of the battery pack includes two end plates 130 arranged opposite to each other along the Y direction, two side plates 120 arranged opposite to each other along the X direction, and a liquid cooling plate 110 arranged at the bottom of the battery 200. The end plates 130, the side plates 120 and the liquid cooling plate 110 form a storage space, and multiple batteries 200 are arranged in the storage space with their large surfaces facing each other along the Y direction. Among them, the battery 200 is a square lithium iron phosphate battery (in other embodiments, a ternary battery, a sodium ion battery, a solid-state or semi-solid-state battery type can also be used), and the outer wall 210 of each battery 200 is covered with an insulating film 300. The insulating film 300 uses a polypropylene insulating film (in other embodiments, a polyethylene terephthalate material can also be used), and an opening area 400 is opened on the insulating film 300 at a portion opposite to any outer wall 210 of the battery 200. The opening area 400 is square and has a square heat dissipation portion 500 therein. The heat dissipation portion 500 uses a thermally conductive graphite sheet (in other embodiments, boron nitride or ceramic sheet can also be used) and is directly attached to the opening area 400.

[0077] The area of ​​the opening region 400 is S mm 2 , the thickness of the insulating film 300 is H mm, and the volume of the battery 200 is V mm 3 , in the battery pack of Example 1, S×H / V=0.2.

[0078] The maximum temperature of the battery pack of this embodiment is measured to be 44.1°C under cooling conditions. Specifically, the maximum temperature can be obtained by the following method: the battery pack with a power level of 80% to 100% is driven by a motor to rotate for 3 hours. The BMS system of the battery pack records the temperature inside the battery pack in real time during these 3 hours and feeds it back to the display device to form a temperature curve. The display device will identify and display the maximum temperature of the battery pack within 3 hours.

[0079] Examples 2 to 30: The test conditions are similar to those of Example 1, except that the area S mm of the opening 400 is 2 , the thickness of the insulating film 300 is H mm, and the volume of the battery 200 is V mm 3 、The volume of the heat dissipation unit 500 is V1mm 3 Adjustments were made respectively and the test data are shown in the table below.

[0080] The experimental conditions of Comparative Examples 1 and 2 are substantially the same as those of Example 1, except that the S×H / V values ​​of Comparative Examples 1 and 2 are 0.00009 and 0.55, respectively, and the maximum temperatures of the battery packs of Comparative Examples 1 and 2 measured under cooling conditions are 65°C and 43°C, respectively.

[0081] Examples 1 to 30, Comparative Example 1 and Comparative Example 2 are as follows:

[0082] Among them, the insulation test is to use an insulation voltage tester to measure the packaged battery pack specimen to be tested. When the displayed insulation resistance is not less than 10 megohms, the insulation performance is recorded as passed, which means that the insulation performance is stable. When the displayed insulation resistance is less than 10 megohms, the insulation performance is recorded as failed, which means that the insulation risk is high.

[0083] It can be seen from the above embodiments and comparative examples that when 0.0001≤S×H / V≤0.5, the temperature of the battery pack can be well controlled. However, when S×H / V<0.0001, the temperature control effect of the battery pack is significantly deteriorated. In addition, when S×H / V>0.5, the temperature control change of the battery pack is not significantly improved compared with the control conditions of the present application, but the risk of insulation failure increases. Therefore, the present application controls S×H / V between 0.0001 and 0.5 to ensure the balance between heat dissipation and insulation effects. In order to further balance the heat dissipation and insulation effects, 0.001≤S×H / V≤0.2 can be selected.

[0084] Furthermore, it can be seen from the above table that when V1 / (S×H)≥1, the maximum temperature of the battery pack is relatively better controlled, that is, the heat dissipation effect is better.

[0085] Accordingly, an embodiment of the present application provides an electrical device, which can be various types of equipment such as new energy vehicles, computers, energy storage and power supply devices, etc. It can be understood that the electrical device can include all the technical features and beneficial effects of the above-mentioned battery pack, which will not be repeated here.

[0086] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0087] The above is a detailed introduction to the battery pack and electrical equipment provided in the embodiments of the present application, and specific examples are used to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application; ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery pack, wherein: include: A frame having a plurality of inner walls, wherein the plurality of inner walls enclose a receiving space; A battery is disposed in the accommodation space, and the battery has a plurality of outer walls; an insulating film covering the plurality of outer walls, the insulating film being provided with an opening area opposite to the outer walls, the opening area being configured to expose at least a portion of the outer walls from the insulating film; A heat dissipation portion, at least a portion of which is disposed in the opening area and between the outer wall and the inner wall; The area of ​​the opening region is S mm 2 , the thickness of the insulating film is H mm, the volume of the battery is V mm 3 , the battery pack satisfies the following relationship: 0.0001≤S×H / V≤0.

5.

2. The battery pack according to claim 1, wherein: The battery pack satisfies the following relationship: 0.001≤S×H / V≤0.

2.

3. The battery pack according to claim 1, wherein: The heat dissipation part is in contact with the inner wall, and the volume of the heat dissipation part is V1mm 3 , the battery pack satisfies the following relationship: V1 / (S×H)≥1.

4. The battery pack according to claim 1, wherein: The outer wall is rectangular, the length of the outer wall is L mm, the maximum dimension of the opening area in the length direction relative to the outer wall is L1 mm, and the battery pack satisfies the following relationship: 0.01≤L1 / L<1.

5. The battery pack according to claim 1, wherein: The outer wall is rectangular, the width of the outer wall is M mm, the maximum dimension of the opening area in the width direction relative to the outer wall is M1 mm, and the battery pack satisfies the following relationship: 0.01≤M1 / M<1.

6. The battery pack according to claim 4, wherein: The battery pack satisfies the following relationship: L1 / L≥0.

5.

7. The battery pack according to claim 5, wherein: The battery pack satisfies the following relationship: M1 / M≥0.

5.

8. The battery pack according to claim 1, wherein: The thickness of the heat dissipation portion is H1 mm, and the battery pack satisfies the following relationship: H1 / H≥1.

9. The battery pack according to claim 1, wherein: The plurality of outer walls include a top wall, a bottom wall, and a plurality of side walls connected between the top wall and the bottom wall; The portion of the insulating film covering the bottom wall is provided with the opening area.

10. The battery pack according to claim 1, wherein: The plurality of outer walls include a top wall, a bottom wall, and a plurality of side walls connected between the top wall and the bottom wall; The portion of the insulating film covering the side wall is provided with the opening area.

11. The battery pack according to claim 9, wherein: The insulating film is provided with a plurality of opening areas; The multiple opening areas include a first opening area and a second opening area arranged on the portion of the bottom wall covered by the insulating film, and the first opening area and the second opening area are both configured to expose a portion of the bottom wall from the insulating film; the heat dissipation portion includes a first heat dissipation portion and a second heat dissipation portion, the first heat dissipation portion is arranged in the first opening area, the second heat dissipation portion is arranged in the second opening area, and the first heat dissipation portion and the second heat dissipation portion are arranged between the bottom wall and the inner wall.

12. The battery pack according to claim 10, wherein: The insulating film is provided with a plurality of opening areas; The plurality of opening regions include a third opening region and a fourth opening region disposed on a portion of the side wall covered by the insulating film, and the third opening region and the fourth opening region are both configured to expose a portion of the side wall to the insulating film; The heat dissipation part includes a third heat dissipation part and a fourth heat dissipation part. The third heat dissipation part is arranged in the third opening area, the fourth heat dissipation part is arranged in the fourth opening area, and the third heat dissipation part and the fourth heat dissipation part are arranged between the side wall and the inner wall.

13. The battery pack according to claim 9, wherein: The frame includes a liquid cooling plate disposed opposite to the bottom wall, the plurality of inner walls include a liquid cooling surface of the liquid cooling plate disposed toward the battery, and the heat dissipation portion is connected between the outer wall and the liquid cooling surface.

14. The battery pack according to claim 10, wherein: The frame includes a liquid cooling plate arranged opposite to the side wall, the plurality of inner walls include a liquid cooling surface of the liquid cooling plate arranged toward the battery, and the heat dissipation portion is connected between the outer wall and the liquid cooling surface.

15. The battery pack according to claim 10, wherein: The plurality of side walls include a first side wall and a second side wall that are oppositely disposed; Portions of the insulating film covering the first side wall and the second side wall are both provided with the opening area.

16. The battery pack according to any one of claims 1 to 15, wherein: The material of the heat dissipation part is one or more of phase change material, thermal conductive glue, and thermal conductive graphite sheet.

17. An electrical device, wherein: A battery pack comprising any one of claims 1 to 16.

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