Protective structure, battery pack and electric device

Abstract

The utility model relates to a protection structure, a battery pack and a power utilization device, the protection structure comprises a protection body and a weak part, the protection body comprises an air leakage hole, and the air leakage hole extends along the thickness direction of the protection body. The weak part is arranged in the air leakage hole and connected with the hole wall of the air leakage hole, and the weak part is configured to be broken when the borne pressure exceeds a threshold value. Wherein the protection body and the weak part are insulating and high-temperature-resistant foam molding parts. According to the technical scheme, the weak part and the protection body are the insulating and high-temperature-resistant foam molding parts, so that even if the battery monomer is subjected to thermal runaway, the protection body and the weak part can effectively insulate the box body and the battery monomer, and the battery monomer is not broken down by high voltage under the thermal runaway high-temperature impact; and the probability of high-voltage arc discharge between the single batteries and the box body is reduced. And moreover, the two parts are foamed molded parts, so that the preparation cost is low, and the protection cost can be reduced. The protection structure provided by the embodiment of the utility model has the effects of economy and relatively good arc discharge prevention effect.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a protective structure, a battery pack and an electrical device. Background Art

[0002] When a battery cell in a battery pack experiences thermal runaway, the ejected material can easily cause high-voltage arcing between other battery cells and the box. Since the temperature at the arcing point is high, it can easily cause thermal runaway in other battery cells, leading to thermal runaway in the entire battery pack. Therefore, it is necessary to take effective protective measures to block the secondary hazards of arcing caused by thermal runaway battery cells. Utility Model Content

[0003] Based on this, it is necessary to provide a protective structure, battery pack and electrical device to address the problem of arcing hazards caused by high voltage after thermal runaway of battery cells in the battery pack, thereby causing large-scale thermal runaway.

[0004] A protective structure, comprising:

[0005] A protective body, the protective body comprising an air leakage hole, the air leakage hole extending along the thickness direction of the protective body; and

[0006] A weak portion, disposed in the air leakage hole and connected to the hole wall of the air leakage hole, wherein the weak portion is configured to break when the pressure it bears exceeds a threshold value;

[0007] Wherein, the protective body and the weak portion are both insulating and high-temperature resistant foamed molded parts.

[0008] In some embodiments, the protective body and the weak portion are integrally foamed.

[0009] In some embodiments, the protective body and the weak portion are both polyurethane foam molded parts or silicone foam molded parts.

[0010] In some embodiments, a minimum dimension H of the weak portion in the thickness direction satisfies: 0.3 mm ≤ H ≤ 10 mm.

[0011] In some embodiments, the weak portion includes a thinned portion, the thinned portion is sealed in the air leakage hole, and the thickness of the thinned portion is smaller than the extension length of the air leakage hole.

[0012] In some embodiments, a minimum dimension h1 of the thinned portion in the thickness direction satisfies: 0.3 mm ≤ h1 ≤ 3 mm.

[0013] In some embodiments, the weak portion includes a notched portion, the notched portion includes a blocking area and a plurality of connecting areas, the plurality of connecting areas are arranged around the periphery of the blocking area and connected between the blocking area and the hole wall of the air leakage hole;

[0014] A gap is formed between the barrier area between adjacent connection areas and the hole wall of the air leakage hole.

[0015] In some embodiments, the minimum dimension h2 of the notch in the thickness direction satisfies: 1 mm ≤ h2 ≤ 10 mm; and / or

[0016] The minimum width w of the gap satisfies: 0<w≤3mm.

[0017] In some embodiments, the weak portion includes multiple groups of the weak portions arranged side by side along the first direction, and each group of the weak portions includes multiple weak portions arranged at intervals along the second direction; the first direction, the second direction, and the thickness direction are not coplanar and intersect with each other.

[0018] In some embodiments, the protective body includes an air leakage channel, and the air leakage channel can connect the air leakage hole with the outside when the weak portion is broken.

[0019] In some embodiments, the air leakage channel includes an air leakage groove, which is recessed on a first surface of the protective body in the thickness direction and can expose the weak portion.

[0020] In some embodiments, it is characterized in that the protective body further includes an avoidance groove, and the avoidance groove is recessed and arranged on the second surface of the protective body in the thickness direction.

[0021] In some embodiments, it is characterized in that the protective body includes an edge portion, which is protruding from the second surface of the protective body in the thickness direction and is arranged around the periphery of the second surface.

[0022] A battery pack, comprising:

[0023] Box;

[0024] A battery cell is contained in the box and has an explosion-proof structure; and

[0025] As described in any of the above embodiments, the protective structure is arranged between the battery cell and the box body, and the weak portion of the protective structure corresponds to the explosion-proof structure.

[0026] In some embodiments, the box body includes a box cover, and the protective structure is disposed between the box cover and the battery cell.

[0027] In some embodiments, the protective body has a first surface and a second surface that are disposed opposite to each other in the thickness direction, the first surface is disposed in contact with the inner wall of the box body, and the second surface is disposed in contact with the surface of the battery cell.

[0028] An electrical device comprises a battery pack as described in any one of the above items, wherein the battery pack is used to provide electrical energy.

[0029] The above-mentioned protective structure, battery pack and electrical device, because their weak parts and protective bodies are all insulating and high-temperature resistant foamed molded parts, even if the battery cell has thermal runaway, the protective body and weak parts can effectively insulate the box body and the battery cell, and will not be broken down by high voltage under the high-temperature impact of thermal runaway of the battery cell, thereby reducing the probability of high-voltage arcing between the battery cell and the box body. Moreover, both are foamed molded parts with low preparation costs, which can reduce the cost of protection. The protective structure provided in the embodiment of the present application is economical and has good anti-arcing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0031] Figure 1 A schematic top view of a protective structure according to some embodiments of the present application;

[0032] Figure 2 for Figure 1 A bottom view schematic diagram of the protective structure shown;

[0033] Figure 3 for Figure 1 A partial cross-sectional view of the protective structure shown;

[0034] Figure 4 Schematic top views of protective structures of other embodiments of the present application;

[0035] Figure 5 for Figure 4 A bottom view schematic diagram of the protective structure shown;

[0036] Figure 6 for Figure 4 The enlarged view of point A in the middle;

[0037] Figure 7 for Figure 4 A partial cross-sectional view of the protective structure shown;

[0038] Figure 8Schematic diagram of the internal structure of the battery pack of some embodiments of the present application.

[0039] The reference numerals in the specific implementation manner are as follows:

[0040] 100, battery pack; 10, protection structure; 11, protection body; 11a, air leakage hole; m1, first surface; m2, second surface; X, first direction; Y, second direction; Z, thickness direction; 11b, air leakage channel; b1, air leakage groove; 11c, avoidance groove; 11d, edge portion; 12, weak portion; 12e, thinning portion; 12f, notched portion; f1, barrier area; f2, connection area; f3, gap; 20, battery cell; 30, box body; 31, box cover; 32, box body. DETAILED DESCRIPTION

[0041] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0042] In the description of the present application, it should be understood that terms such as “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships, if any, are 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, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0043] In addition, if present, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0044] In this application, unless otherwise clearly specified and limited, if any, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0045] In the present application, if it appears, unless otherwise clearly specified and limited, a first feature “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature “above”, “above” and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature “below”, “below” and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0046] It should be noted that, if present, when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0047] The embodiments of the present application provide a protective structure to address the problem of large-area thermal runaway caused by high-voltage arcing between the battery cell and the box when a single battery cell in a battery pack thermally runs away.

[0048] The protective structure provided in the embodiment of the present application can be applied to a battery pack and arranged between the case and the battery cell of the battery pack to reduce the probability of high-temperature arcing between the battery cell and the case, thereby reducing the risk of large-area thermal runaway caused by this and improving the reliability of the battery pack. A plurality of battery cells can be accommodated in the case. The plurality of battery cells can be connected in series, in parallel, or in mixed connection. Mixed connection means that the plurality of battery cells are both connected in series and in parallel. The battery may also include other structures. For example, the battery may also include a busbar component for realizing electrical connection between the plurality of battery cells. Generally, the protective structure may be arranged between the case and the plurality of battery cells.

[0049] The battery cell may be a secondary battery or a primary battery, and the battery cell may be a lithium sulfur battery, a sodium ion battery or a magnesium ion battery, but is not limited thereto. The battery cell may be cylindrical, flat, rectangular or in other shapes.

[0050] A battery cell usually includes a battery case, an electrode assembly contained between the battery cases, and an electrolyte disposed in the battery case. The electrolyte can be solid or liquid. The electrode assembly is the smallest unit in the battery pack for electrochemical reactions, which enables the charging and discharging of the battery cell, and usually includes a positive electrode sheet, a negative electrode sheet, and an isolation membrane separating the positive electrode sheet from the negative electrode sheet. The battery cell usually also includes an explosion-proof structure, which is disposed on the battery case. The explosion-proof structure can explode when the internal pressure of the battery cell reaches a relevant threshold, and connect the inside and outside of the battery cell to relieve pressure. The explosion-proof structure can be an explosion-proof valve, notch and other structures. The battery cell usually also includes a positive electrode column and a negative electrode column, which are used to connect the battery cell to an external circuit.

[0051] The battery pack in the embodiment of the present application can be applied to an electrical device to provide electrical energy for the electrical device. The electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, etc. Taking the electrical device as a vehicle as an example, the battery can be set at the rear, front or bottom of the vehicle, and the battery can provide electrical energy for the drive of the vehicle, and can also provide electrical energy for the control system of the vehicle.

[0052] The protective structure in the embodiment of the present application is described in detail below.

[0053] According to one or more embodiments of the present application, please refer to Figure 1 and Figure 4 The protective structure 10 provided in the embodiment of the present application includes a protective body 11 and a weak portion 12. The protective body 11 includes an air leakage hole 11a, and the air leakage hole 11a is extended along the thickness direction Z of the protective body 11. The weak portion 12 is arranged in the air leakage hole 11a and connected to the hole wall of the air leakage hole 11a. The weak portion 12 is configured to break when the pressure it bears exceeds a threshold. Among them, the protective body 11 and the weak portion 12 are both insulating and high temperature resistant foam moldings.

[0054] In actual application, the protective body 11 is located in the box body 30 and is disposed between the battery cell 20 and the inner wall of the box body 30. Specifically, the protective body 11 can be clamped between the inner wall of the box body 30 and the battery cell 20 to achieve the fixation of its own position. Of course, the protective body 11 can also be disposed on the box body 30 and / or the battery cell 20 by bonding or other methods.

[0055] Under normal application, among the multiple battery cells 20 in the battery pack 100, the side surface where the explosion-proof structure is located is arranged on the same side of the multiple battery cells 20, which is defined as the explosion-proof side, and the protective body 11 is arranged between the explosion-proof side of the battery cell 20 and the box body 30. The vent holes 11a of the protective body 11 are arranged corresponding to the explosion-proof structure of the battery cell 20. When the explosion-proof structure on the battery cell 20 explodes, its high-pressure smoke can flow toward the vent holes 11a.

[0056] The vent hole 11a is usually a straight hole, which is extended along the thickness direction Z of the protective body 11. The vent hole 11a can be a circular hole, a square hole, an elliptical hole, a polygonal hole, etc., and the specific cross-sectional shape is not limited. A plurality of vent holes 11a can be provided on the protective body 11. In practical applications, each vent hole 11a can correspond to at least one explosion-proof structure of at least one battery cell 20. Usually, each vent hole 11a corresponds to one explosion-proof structure of one battery cell 20.

[0057] A weak portion 12 is provided in the air leakage hole 11a, and the weak portion 12 is connected to the hole wall of the air leakage hole 11a. Figure 1 and Figure 2 It is understood that the periphery of the weak portion 12 can be completely connected to the hole wall of the pressure relief hole to block the pressure relief hole. Figure 4 and Figure 6 It is understood that a gap f3 can be formed between the periphery of the weak portion 12 and the hole wall of the pressure relief hole. It is understood that the design of the weak portion 12 should satisfy that when the air pressure on the side where the battery cell 20 is located exceeds the threshold, the weak portion 12 can be broken (i.e., broken by the high-pressure flue gas) to completely open the gas relief hole 11a or open a larger flow area, allowing the explosion-proof structure of the battery cell 20 to explode, and the high-pressure flue gas inside the battery cell 20 can be quickly discharged from the battery cell 20 through the gas relief hole 11a, thereby reducing the explosion probability of the battery cell 20. Among them, the rupture of the weak portion 12 includes the disconnection between the weak portion 12 and the hole wall of the gas relief hole 11a and the disconnection / fragmentation of the weak portion 12 itself.

[0058] Understandably, the explosion-proof structure of the battery cell 20 is isolated from the box body 30 by the weak portion 12. Both the protective body 11 and the weak portion 12 are insulating and high-temperature resistant parts. Among them, both the protective body 11 and the weak portion 12 have insulating properties, which can enable the protective structure 10 to insulate and isolate the battery cell 20 from the box body 30, greatly reducing the probability of high-voltage arcing between the box body 30 and the battery cell 20. Both the protective body 11 and the weak portion 12 have high-temperature resistance. When the battery cell 20 has thermal runaway, the protective body 11 and the weak portion 12 can also be more effectively insulated and isolated between the box body 30 and the battery cell 20.

[0059] At the same time, the protective body 11 and the weak portion 12 are both foamed parts, that is, they are formed by a foaming process. The foaming process is a conventional molding method in this field, and the specific principle is not described here. The protective body 11 and the weak portion 12 can be obtained by integral foaming, or they can be foamed separately and then connected together. It should be noted that after foaming, the protective body 11 and the weak portion 12 can also undergo post-processing operations such as machining.

[0060] In actual application, the protective structure 10 is firstly foamed by an external mold to obtain a blank, the blank is machined and processed to obtain a final product, and then the protective structure 10 is placed between the battery cell 20 and the box body 30 .

[0061] The above-mentioned protective structure 10, because its weak part 12 and protective body 11 are both insulating and high temperature resistant foamed molded parts, even if the battery cell 20 has thermal runaway, the protective body 11 and the weak part 12 can also effectively insulate the box body 30 and the battery cell 20, and the battery cell 20 will not be broken down by high voltage under the high temperature impact of thermal runaway, and the probability of high voltage arcing between the battery cell 20 and the box body 30 is reduced. Moreover, both are foamed molded parts, and the preparation cost is relatively low, which can reduce the protection cost. The protective structure 10 provided in the embodiment of the present application is economical and has a good anti-arcing effect.

[0062] In some embodiments, the protective body 11 and the weak portion 12 are integrally foamed. That is, the two are formed through the same foaming process. Specifically, the integral foaming of the protective body 11 and the weak portion 12 can be achieved through the reasonable design of the external mold. In this way, it is helpful to reduce the preparation cost of the protective structure 10, which is more economical.

[0063] In some embodiments, the protective body 11 and the weak portion 12 are both polyurethane foam moldings or silicone foam moldings. That is, the protective body 11 can be a polyurethane foam molding or a silicone foam molding, and the weak portion 12 can be a polyurethane foam molding or a silicone foam molding. Usually, the protective body 11 and the weak portion 12 are made of the same material. Both polyurethane and silicone have good insulation and high temperature resistance, meeting the use requirements of the protective structure 10.

[0064] In some embodiments, reference Figure 3 and Figure 7 , the minimum dimension H of the weak portion 12 in the thickness direction Z satisfies: 0.3mm≤H≤10mm.

[0065] It has been proved by experiments that, under this thickness dimension, the protective structure 10 will not be broken down when it is connected to a DC voltage of 400V to 800V at an ambient temperature of 100°C to 400°C. In this way, the protective structure 10 can play a better anti-arcing effect. At the same time, it has been proved by experiments that, under this thickness dimension, when the battery cell 20 has a thermal runaway, the weak part 12 can be effectively broken / broken by the high-pressure flue gas, so as to smoothly and quickly discharge the high-pressure flue gas generated by the thermal runaway. As an example, the protective structure 10 made of polyurethane integral foaming with an H value of 0.3mm can protect against a DC high-voltage breakdown of 800V and 300°C. As another example, the protective structure 10 made of silicone integral foaming with an H value of 3mm can protect against a DC high-voltage breakdown of 800V and 200°C.

[0066] Generally, the position where the minimum dimension H of the weak portion 12 in the thickness direction Z (ie, the minimum thickness of the weak portion 12) is located is the fracture position of the weak portion 12. To simplify the design, generally, the thickness dimensions of the weak portion 12 are equal at all locations.

[0067] Specifically, H can take the value of 0.3mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm and any value between adjacent values.

[0068] In some embodiments, the weak portion 12 includes a thinned portion 12e, the thinned portion 12e is sealed in the air leakage hole 11a, and the thickness of the thinned portion 12e is less than the extension length of the air leakage hole 11a.

[0069] The extended length of the vent hole 11a is the length in the thickness direction Z of the protective body 11. Usually, the vent hole 11a is set through along the thickness direction Z of the protective body 11. The thinned portion 12e is thinner than the extended length of the vent hole 11a. The extended direction of the vent hole 11a is usually equivalent to the thickness of the protective body 11 region where the vent hole 11a is located. The thickness of the thinned portion 12e is less than the thickness of the protective body 11 region where the vent hole 11a is located, that is, the thinned portion 12e is thinned relative to the protective body 11.

[0070] The periphery of the thinned portion 12e is connected to the hole wall of the air leakage hole 11a, thereby blocking the air leakage hole 11a. Figure 3 As shown, the thinning portion 12e can be arranged at the end of the vent hole 11a in the thickness direction Z and flush with the surface of the protective body 11. Specifically, the thinning portion 12e can be arranged in the middle of the vent hole 11a and not flush with the surface of the protective body 11.

[0071] At this time, the weak portion 12 is designed by locally thinning the thickness. During the foaming process, the protective structure 10 can be obtained by one-time molding using an external mold without subsequent machining to process the weak portion 12, which helps to improve the production efficiency of the protective structure 10.

[0072] In some embodiments, reference Figure 3 , the minimum dimension h1 of the thinned portion 12e in the thickness direction Z satisfies: 0.3mm≤h1≤3mm.

[0073] Generally, the dimension of the thinned portion 12e in the thickness direction Z (ie, the thickness of the thinned portion 12e) is equal everywhere.

[0074] Since the periphery of the thinned portion 12e is connected to the hole wall of the vent hole 11a, the connection strength between the two is relatively large, so when the thickness of the thinned portion 12e is small, it is easier to achieve the rupture of the thinned portion 12e, ensuring the effectiveness of the discharge of high-temperature and high-pressure smoke when the battery cell 20 is in thermal runaway. At this time, the minimum size h1 of the thinned portion 12e is between 0.3mm and 3mm, which can not only have a good high-pressure arc protection effect, but also can break through smoothly and effectively discharge high-temperature hot fluid.

[0075] Specifically, h1 can be 0.3mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm and any value between adjacent values.

[0076] In some embodiments, reference Figure 6 The weak portion 12 includes a notched portion 12f, which includes a blocking area f1 and a plurality of connecting areas f2, which are arranged around the periphery of the blocking area f1 and connected between the blocking area f1 and the hole wall of the air leakage hole 11a. A gap f3 is formed between the blocking area f1 and the hole wall of the air leakage hole 11a between adjacent connecting areas f2.

[0077] The barrier region f1 is used for insulation between the box body 30 and the battery cell 20, and is connected to the hole wall of the air leakage hole 11a via the connection region f2. Generally, the thickness of the barrier region f1 is equal to the thickness of the connection region f2. For ease of understanding, the connection region f2 is protruded relative to the barrier region f1 toward the hole wall of the air leakage hole 11a.

[0078] There are two or more connection areas f2, each of which is connected to the hole wall of the air leakage hole 11a and the barrier area f1, and the connection areas f2 are arranged at intervals along the circumference of the barrier area f1. A gap f3 is formed between the barrier area f1 and the hole wall of the air leakage hole 11a between adjacent connection areas f2. In practical applications, the gap f3 can be processed on the thinning part 12e to obtain the notched part 12f. It can be understood that the number of the gap f3 is at least two, which depends on the number of connection areas f2.

[0079] At this time, the barrier area f1 is connected to the hole wall of the air leakage hole 11a through the connection area f2, and there is a gap f3 between the barrier area f1 and the hole wall of the air leakage hole 11a. Due to the existence of the gap f3, when the explosion-proof structure explodes, within a certain initial air pressure range, high-temperature smoke can be discharged through the gap f3. In this way, in the case of a weak degree of thermal runaway, the gap f3 can realize the discharge of hot fluid without damaging the structure of the protective structure 10, which helps to extend the service life of the protective structure 10.

[0080] In some embodiments, reference Figure 7 , the minimum dimension h2 of the notched portion 12f in the thickness direction Z satisfies: 1mm≤h2≤10mm.

[0081] Generally, the thickness of the connection area f2 is equal to the thickness of the barrier area f1, and the minimum dimension h2 of the notch portion 12f in the thickness direction Z is equal to the thickness of the connection area f2 and the thickness of the barrier area f1. Specifically, h2 can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, and values ​​between adjacent values.

[0082] Since there is a gap f3 in the notch 12f, the hot fluid can be discharged through the gap f3 under appropriate air pressure. When the battery cell 20 has a serious thermal runaway, when the size h2 of the notch 12f is within the above range, the high-pressure flue gas breaks through the notch 12f to be quickly discharged.

[0083] It should be noted that the broken portion of the notched portion 12f may be the connecting region f2, or the blocking region f1, or both.

[0084] In some embodiments, the minimum width w of the gap f3 satisfies: 0<w≤3mm. The width of the gap f3 refers to the vertical distance between the outer peripheral surface of the barrier region f1 and the hole wall of the vent hole 11a. Specifically, the minimum width w of the gap f3 can be 0.1mm, 0.5mm, 0.8mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm and values ​​between adjacent values. When w is within the above range, the notched portion 12f has a better arc-prevention effect.

[0085] In some embodiments, in combination Figure 1 and Figure 4 The weak parts 12 include a plurality of weak parts 12, which are arranged in a plurality of groups along the first direction X, and each group of weak parts 12 includes a plurality of weak parts 12 arranged at intervals along the second direction Y. The first direction X, the second direction Y, and the thickness direction Z are not coplanar and intersect each other.

[0086] Taking the protective body 11 as a rectangular parallelepiped structure as an example, the first direction X may be the width direction of the protective body 11, and the second direction Y may be the length direction of the protective body 11. In practical applications, the second direction Y may be the arrangement direction of the battery cells 20 in the battery pack 100, that is, a plurality of battery cells 20 are arranged in sequence along the second direction Y to form a battery module. The protective structure 10 may be disposed between the battery module and the box 30.

[0087] At this time, the protection structure 10 can be simultaneously disposed between a plurality of battery cells 20 and the box body 30 , and the protection efficiency is high.

[0088] Part of the weak portions 12 may be thinned portions 12e, part of the weak portions 12 may be notched portions 12f, all of the weak portions 12 may be thinned portions 12e, or all of the weak portions 12 may be notched portions 12f.

[0089] In some embodiments, the protective body 11 includes a gas leakage channel 11b, which can connect the gas leakage hole 11a with the outside when the weak part 12 is broken. The gas leakage channel 11b is arranged on the protective body 11, and can be a hole, groove or other structure. When the battery cell 20 fails due to thermal failure and the weak part 12 is broken, the high-temperature hot fluid flows into the gas leakage channel 11b through the gas leakage hole 11a, and then is discharged outward through the gas leakage channel 11b. At this time, the setting of the gas leakage channel 11b can help the smoke generated by the thermal runaway of the battery cell 20 to be discharged smoothly, and help to suppress the spread of heat.

[0090] Specifically, during application, the air leakage channel 11 b is connected to the interior of the box body 30 of the battery pack 100 and the air leakage hole 11 a.

[0091] In some embodiments, the air leakage channel 11 b includes an air leakage groove b1 , which is recessed on the first surface m1 of the protective body 11 in the thickness direction Z and can expose the weak portion 12 .

[0092] The protective body 11 has a first surface m1 and a second surface m2 disposed opposite to each other in the thickness direction Z. In practical application, the first surface m1 is disposed facing the inner wall of the box body 30, and the second surface m2 is disposed facing the battery cell 20. A gas relief groove b1 is formed in a depression on the first surface m1. Specifically, the gas relief groove b1 can be extended along the second direction Y, thereby guiding the smoke to flow in the second direction Y.

[0093] The air leakage hole 11a penetrates the bottom of the air leakage groove b1, so that the air leakage groove b1 can expose the weak part 12. In this way, the smoke flowing out of the air leakage hole 11a can quickly enter the air leakage groove b1, and the exhaust is faster.

[0094] In some embodiments, the protective body 11 further includes an avoidance groove 11 c , which is recessed on the second surface m2 of the protective body 11 in the thickness direction Z.

[0095] Specifically, a plurality of avoidance grooves 11c may be recessed on the second surface m2. In some cases, the poles of the battery cell 20 and the explosion-proof structure are arranged on the same side, and the avoidance grooves 11c can be used to avoid the poles on the battery cell 20, facilitating electrical connection between the poles of the battery cell 20.

[0096] Specifically in the embodiment, the weak portions 12 are arranged in multiple rows in the first direction X, and each row of weak portions 12 is provided with multiple weak portions 12 at intervals in the second direction Y. Avoidance grooves 11c are arranged on both sides of each row of weak portions 12 in the second direction Y. In actual application, poles are provided on both sides of the explosion-proof structure on the same battery cell 20, the explosion-proof structure is provided corresponding to the weak portion 12, and the poles on both sides are provided corresponding to the avoidance grooves 11c on both sides of the weak portion 12.

[0097] In some embodiments, reference Figure 2 and Figure 5 The protective body 11 includes an edge portion 11d, which is protruding from the second surface m2 of the protective body 11 in the thickness direction Z and is arranged around the periphery of the second surface m2. Specifically, the edge portion 11d is arranged in a circle around the periphery of the second surface m2, and a certain gap may be formed on the edge portion 11d.

[0098] In actual application, the edge portion 11d can be sleeved on a battery module formed by a plurality of battery cells 20, so that the protective structure 10 can be better positioned and installed.

[0099] In addition, refer to Figure 7 The embodiment of the present application further provides a battery pack 100, comprising a box body 30, a battery cell 20 and a protective structure 10 in any of the above embodiments, wherein the battery cell 20 is contained in the box body 30 and has an explosion-proof structure. The protective structure 10 is disposed between the battery cell 20 and the box body 30, and the weak portion 12 of the protective structure 10 corresponds to the explosion-proof structure.

[0100] The battery pack 100 has all the beneficial effects of the above-mentioned embodiments, which will not be described in detail here.

[0101] In some embodiments, reference Figure 7The box body 30 includes a box cover 31, and the protective structure 10 is arranged between the box cover 31 and the battery cell 20. Usually, the explosion-proof structure of the battery cell 20 is arranged on its top surface and is arranged opposite to the box cover 31. At this time, the protective structure 10 can effectively prevent the generation of high-voltage arc between the box cover 31 and the battery cell 20.

[0102] Understandably, the box body 30 also includes a box body 32, the box body 32 encloses a receiving cavity with one end open, the box cover 31 covers the open end of the receiving cavity, and the battery cell 20 is arranged in the receiving cavity. The box cover 31 and the box body 32 are usually detachably connected.

[0103] In some embodiments, the protective body 11 has a first surface m1 and a second surface m2 disposed opposite to each other in the thickness direction Z, the first surface m1 is disposed in contact with the inner wall of the box body 30, and the second surface m2 is disposed in contact with the surface of the battery cell 20. That is, the protective body 11 is in contact with the inner wall of the box body 30 through its first surface m1, and is in contact with the end surface of the battery cell 20 through its second surface m2, so that the protective body 11 can be positioned and fixed by the box body 30 and the battery cell 20, simplifying the installation of the protective structure 10.

[0104] In addition, the present application also provides an electrical device, including the battery pack 100 in any of the above embodiments, and the battery pack 100 is used to provide electrical energy.

[0105] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0106] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A protective structure (10), characterized in that: The protective structure (10) comprises: A protective body (11), the protective body (11) comprising an air leakage hole (11a), the air leakage hole (11a) extending along a thickness direction (Z) of the protective body (11); and A weak portion (12) is disposed in the air leakage hole (11a) and connected to the hole wall of the air leakage hole (11a), and the weak portion (12) is configured to break when the pressure it bears exceeds a threshold value; Wherein, the protective body (11) and the weak portion (12) are both insulating and high-temperature resistant foamed molded parts.

2. The protective structure (10) according to claim 1, characterized in that: The protective body (11) and the weak portion (12) are integrally foamed; and / or, The protective body (11) and the weak portion (12) are both polyurethane foam moldings or silicone foam moldings; and / or, The minimum dimension H of the weak portion (12) in the thickness direction (Z) satisfies: 0.3 mm ≤ H ≤ 10 mm.

3. The protective structure (10) according to claim 1, characterized in that: The weak portion (12) comprises a thinned portion (12e), the thinned portion (12e) is sealed in the air leakage hole (11a), and the thickness of the thinned portion (12e) is smaller than the extension length of the air leakage hole (11a).

4. The protective structure (10) according to claim 3, characterized in that: The minimum dimension h1 of the thinned portion (12e) in the thickness direction (Z) satisfies: 0.3mm≤h1≤3mm.

5. The protective structure (10) according to claim 1, characterized in that: The weak portion (12) comprises a notched portion (12f), the notched portion (12f) comprises a barrier region (f1) and a plurality of connection regions (f2), the plurality of connection regions (f2) being arranged around the periphery of the barrier region (f1) and connected between the barrier region (f1) and the hole wall of the air leakage hole (11a); A gap (f3) is formed between the barrier area (f1) located between adjacent connection areas (f2) and the hole wall of the air leakage hole (11a).

6. The protective structure (10) according to claim 5, characterized in that: The minimum dimension h2 of the notched portion (12f) in the thickness direction (Z) satisfies: 1mm≤h2≤10mm; and / or The minimum width w of the gap (f3) satisfies: 0<w≤3mm.

7. The protective structure (10) according to claim 1, characterized in that: The weak portions (12) include a plurality of weak portions (12), and the plurality of weak portions (12) are arranged side by side in a plurality of groups along a first direction (X), and each group of the weak portions (12) includes a plurality of the weak portions (12) arranged at intervals along a second direction (Y); the first direction (X), the second direction (Y), and the thickness direction (Z) are not coplanar and intersect with each other.

8. The protective structure (10) according to claim 1, characterized in that: The protective body (11) comprises an air leakage channel (11b), and the air leakage channel (11b) can connect the air leakage hole (11a) with the outside when the weak portion (12) is broken.

9. The protective structure (10) according to claim 8, characterized in that: The air release channel (11b) comprises an air release groove (b1), wherein the air release groove (b1) is recessed on a first surface (m1) of the protective body (11) in the thickness direction (Z) and is capable of exposing the weak portion (12).

10. The protective structure (10) according to any one of claims 1 to 9, characterized in that: The protective body (11) further comprises an avoidance groove (11c), wherein the avoidance groove (11c) is recessed and arranged on a second surface (m2) of the protective body (11) in the thickness direction (Z).

11. The protective structure (10) according to any one of claims 1 to 9, characterized in that: The protective body (11) comprises an edge portion (11d), wherein the edge portion (11d) is protrudingly arranged on a second surface (m2) of the protective body (11) in the thickness direction (Z), and is arranged around the periphery of the second surface (m2).

12. A battery pack (100), characterized in that: include: Box body (30); A battery cell (20) is contained in the box (30) and has an explosion-proof structure; and The protective structure (10) according to any one of claims 1 to 11, wherein the protective structure (10) is arranged between the battery cell (20) and the box body (30), and the weak portion (12) of the protective structure (10) is arranged corresponding to the explosion-proof structure.

13. The battery pack (100) according to claim 12, characterized in that: The box body (30) comprises a box cover (31), and the protective structure (10) is arranged between the box cover (31) and the battery cell (20).

14. The battery pack (100) according to claim 12, characterized in that: The protective body (11) has a first surface (m1) and a second surface (m2) disposed opposite to each other in the thickness direction (Z); the first surface (m1) is disposed in contact with the inner wall of the box body (30); and the second surface (m2) is disposed in contact with the surface of the battery cell (20).

15. An electrical device, characterized in that: Comprising a battery pack (100) as claimed in any one of claims 12 to 14, the battery pack (100) being used for providing electrical energy.

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