WO2024098401A1

WO2024098401A1 - Battery end cover assembly, energy storage apparatus, and electrical device

Info

Publication number: WO2024098401A1
Application number: PCT/CN2022/131476
Authority: WO
Inventors: 梁金云; 张亮亮; 张万财; 阳明
Original assignee: 深圳海润新能源科技有限公司; 厦门海辰储能科技股份有限公司
Priority date: 2022-11-11
Filing date: 2022-11-11
Publication date: 2024-05-16

Abstract

Disclosed in the present application are a battery end cover assembly, an energy storage apparatus, and an electrical device. The battery end cover assembly comprises: an end cover; terminal assemblies, connected to the upper surface of the end cover; and a pressure relief mechanism, provided on the end cover. A graphic area formed by the outer contour of the end cover is a first area S1, and the projection area of the pressure relief mechanism on the end cover is a second area S2, S2/S1 being 0.5%-5%.

Description

Battery end cap assembly, energy storage device and electrical equipment

Technical Field

The present application relates to the field of battery technology, and in particular to a battery end cover assembly, an energy storage device, and an electrical device.

Background technique

In the related art, mobile phones, laptop computers, power tools, electric vehicles, etc., all use batteries as power sources. For example, electric vehicles need to use a power battery pack composed of multiple batteries.

The battery is equipped with an explosion-proof pressure relief structure on the cover, for example, a thin-walled valve body is arranged on the battery cover. When the internal pressure of the battery exceeds the specified value, the thin wall of the valve body ruptures to release the internal pressure and prevent the battery from bursting. In the existing scheme, the specifications of the explosion-proof pressure relief structure are relatively fixed, and there is a situation where the pressure relief pressure is too large, resulting in untimely pressure relief, which affects the safety of the battery.

Summary of the invention

The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a battery end cover assembly, so that the area occupied by the pressure relief mechanism is more matched with the end cover area, thereby matching the pressure relief capacity of the battery.

The present application further proposes an energy storage device using the above-mentioned battery end cover assembly.

The present application also proposes an electrical device using the above energy storage device.

According to the battery end cap assembly of the first embodiment of the present application, it includes: an end cap; a terminal assembly, the terminal assembly is connected to the end cap; a pressure relief mechanism, the pressure relief mechanism is arranged on the end cap, and the pressure relief mechanism and the terminal assembly are spaced apart along the length direction of the end cap; wherein the graphic area formed by the outer contour of the end cap is the first area S1, the projection area of the pressure relief mechanism on the end cap is the second area S2, and the second area S2 accounts for 0.5%-5% of the first area S1. The dimension of the pressure relief mechanism along the length direction of the end cap is b1, and the proportion of b1 to the length b0 of the end cap is 5% to 12%; the dimension of the pressure relief mechanism along the width direction of the end cap is e1, and the proportion of e1 to the width e0 of the end cap is 15% to 25%.

According to the battery end cap assembly of the first embodiment of the present application, by limiting the second area S2 to account for no less than 0.5% of the first area S1, the area occupied by the pressure relief mechanism will not be too small, and after the pressure relief mechanism is opened, there is a sufficiently large pressure relief port to exhaust gas, so that the size of the battery end cap assembly is more matched with the pressure relief capacity, reducing the probability of untimely pressure relief and improving battery safety. By limiting the second area S2 to account for no more than 5% of the first area S1, the area occupied by the pressure relief mechanism will not be too large, so that the overall structural strength of the battery end cap assembly can be ensured, and the battery end cap assembly is not easily deformed after being under pressure.

By controlling the ratio of the length b1 of the pressure relief mechanism to the length b0 of the end cover to at least 5%, the pressure relief mechanism can occupy a large enough area for pressure relief and exhaust, ensuring the smoothness of exhaust; limiting the ratio of the length b1 of the pressure relief mechanism to the length b0 of the end cover to no more than 12%, a certain space can be freed up on the end cover to place the terminal assembly, so that the pressure relief mechanism and the terminal assembly do not need to be set too close to each other, which may cause inconvenience in installation or even mutual interference. In addition, limiting the length b1 of the pressure relief mechanism can avoid the pressure relief mechanism being too long, resulting in excessive bending moment and deformation, thereby avoiding the pressure relief mechanism from being easy to fall off due to excessive deformation, thus avoiding the problem that the pressure relief mechanism is sprayed away from the end cover by high-pressure gas at high pressure, resulting in the exhaust direction being unable to be limited and the exhaust being hindered by the detached pressure relief mechanism.

The ratio of the width e1 of the pressure relief mechanism to the width e0 of the end cover is at least 15%, so that the pressure relief mechanism can occupy a large enough area for pressure relief and exhaust to ensure smooth exhaust. By controlling the ratio of the width e1 of the pressure relief mechanism to the width e0 of the end cover to not exceed 25%, the possibility of the side of the end cover on the pressure relief mechanism being too narrow and easy to break is reduced, thereby avoiding the risk of the pressure relief mechanism easily falling off the end cover.

In summary, by limiting the area ratio, length ratio and width ratio of the pressure relief mechanism on the end cover, the pressure relief mechanism can occupy a large enough area for pressure relief and exhaust, ensuring smooth and timely exhaust; at the same time, the end cover does not need to be set too narrow on each side of the pressure relief mechanism to avoid the risk of the edge of the end cover being easily broken due to the pressure relief mechanism being too long or too wide, and to avoid the end cover from bending or breaking when it is impacted or under pressure. Moreover, there is enough space on the end cover to arrange the components so that the components can be spaced apart without interfering with each other. In addition, the structural strength of the end cover can be guaranteed to avoid the end cover from bending or breaking when it is impacted or under pressure. Avoid excessive deformation of the end cover when it is under pressure, avoid the possibility of gas exhausting from the edge of the end cover when the temperature or pressure in the battery is too high, and ensure that the gas is exhausted only from the pressure relief mechanism, which can effectively control the exhaust direction of the gas inside the battery, facilitate the post-processing of the discharged electrolyte or high-temperature gas, and avoid the arbitrary discharge of electrolyte or high-temperature gas in the battery to cause unnecessary corrosion, fire, etc.

In some embodiments, the pressure relief mechanism includes an explosion-proof valve, and the explosion-proof valve includes an opening area; a notch groove is provided on the explosion-proof valve, and the notch groove is located in the opening area.

Therefore, the explosion-proof valve is used for pressure relief. Compared with the pressure relief valve, one-way valve and other components, the explosion-proof valve is thinner and does not require too much space for the pressure relief mechanism, which is conducive to increasing the density of the internal structure of the battery, thereby increasing the energy density of the battery. Moreover, after the internal structure of the battery is tightly arranged, it is also conducive to improving the structural strength.

Specifically, the minimum thickness of the explosion-proof valve at the notch groove is the first thickness n1, and the thickness of the explosion-proof valve at the opening area is the second thickness n2, and the first thickness n1 is 15% to 25% of the second thickness n2. Here, the thickness ratio of the explosion-proof valve at the notch groove and at the opening area is limited, and while the explosion-proof valve is thinner at the notch groove, the thickness of the opening area will not be too thick. The thickness of the explosion-proof valve at the notch groove is thinner, so that the explosion-proof valve can be broken in time at the notch groove when the internal pressure or temperature of the battery reaches the threshold. The thickness of the opening area will not be too thick, so that the opening area is easily opened by high-pressure gas after the notch groove is broken, so that the pressure relief port can be fully opened and exhaust smoothly. By limiting the thickness of the explosion-proof valve at the opening area to at least four times the thickness at the notch groove, when the explosion-proof valve is subjected to internal pressure shock or the temperature is too high, the pressure can be concentrated at the notch groove, and the explosion-proof valve is concentrated at the notch groove and breaks, and the exhaust is more timely, which is conducive to improving the working sensitivity of the explosion-proof valve.

Specifically, the projection area of the notch groove on the end cover is the third area S3, and the third area S3 accounts for 1.0% to 1.5% of the second area S2. As a result, the proportion of the third area S3 on the second area S2 will not be too small. When the internal pressure or temperature of the battery reaches the threshold, there will be more area at the notch groove to sense the pressure or temperature change, so as to break and release the pressure in time, thereby improving the sensitivity of the explosion-proof valve. Limiting the proportion of the third area S3 on the second area S2 does not affect the timely breaking of the explosion-proof valve when the internal pressure or temperature of the battery changes, but the smaller third area S3 can effectively avoid the external impact force acting on the notch groove, and avoid the explosion-proof valve from breaking when the battery end cover assembly is accidentally bumped, thereby improving the stability of the explosion-proof valve.

Optionally, the tensile strength of the explosion-proof valve is 90 to 130 N/mm ^{^2} . Within this tensile strength range, the explosion-proof valve can withstand a pressure of approximately 0.4-0.8 Mpa. Therefore, the tensile strength of the explosion-proof valve should not be lower than 90 N/mm ^{^2} , so that the explosion-proof valve can withstand a pressure far lower than 0.4 Mpa, and the explosion-proof valve can be prevented from breaking due to temporary local heating or pressure increase inside the battery, so that the explosion-proof valve will not be damaged under reasonable temperature or pressure changes, and the failure rate of the explosion-proof valve will be reduced. The tensile strength of the explosion-proof valve should not be higher than 130 N/mm ^{^2} , so that the explosion-proof valve can withstand a pressure far higher than 0.8 Mpa, and the explosion-proof valve has not been broken when there is an explosion risk inside the battery, and the explosion-proof valve can be opened in time to exhaust. Choose a suitable tensile strength for the explosion-proof valve, so that the explosion-proof valve is not easily damaged during processing and assembly, and the production defect rate of the battery end cover assembly is reduced.

In some specific embodiments, the outline of the notched groove on the cross section perpendicular to the extension direction of the notched groove is U-shaped or C-shaped. Compared with the notched groove with a rectangular, trapezoidal, or triangular cross section, the notched groove with a U-shaped or C-shaped cross section outline avoids sharp corners, avoids excessive concentrated stress at the weakest point of the explosion-proof valve, and thus reduces the possibility of the explosion-proof valve breaking due to excessive concentrated stress before reaching the set tolerance pressure. Therefore, such a setting can improve the reliability of the explosion-proof valve. As far as the production of explosion-proof valves is concerned, the notched groove is usually formed by cutting or stamping. Since the cross section outline of the notched groove perpendicular to the extension direction of the notched groove is U-shaped or C-shaped, the sharp corner design is avoided, and excessive burrs due to sharp corners are avoided during processing, and the possibility of the sharp corners being torn due to pulling burrs during production is avoided, thereby avoiding the reduction of the pressure resistance value of the explosion-proof valve.

Optionally, the contour line of the scored groove on the cross section perpendicular to the extension direction of the scored groove includes an arc line, and the radius r1 of the arc line is 0.05-0.15mm. Thus, limiting the range of the arc line radius r1 is conducive to the uniform distribution of the internal stress of the explosion-proof valve on the wall surface of the scored groove along the arc line, greatly reducing the internal stress difference at various points along the arc line. In this way, when the internal pressure or temperature of the battery changes and causes the explosion-proof valve to deform, the explosion-proof valve breaks open at the scored groove due to deformation. At this time, the explosion-proof valve breaks open at the scored groove mainly due to changes in internal temperature and pressure, and the influence of concentrated internal stress is reduced, thereby making the actual withstand voltage value of the explosion-proof valve more accurate.

In some embodiments, the minimum spacing between the pressure relief mechanism and the terminal assembly is b2, b2>b1. In this way, the terminal assembly and other external components connected to the terminal assembly can be separated from the pressure relief mechanism by a sufficient distance. After the pressure relief mechanism is opened, other external components are not easy to block the pressure relief mechanism, which can reduce the probability of internal gas and electrolyte spraying onto the terminal assembly and other external components when the pressure relief mechanism releases pressure, and reduce the possibility of fire in other external components. Moreover, after the pressure relief mechanism is separated from the terminal assembly by a safe distance, the spray from the pressure relief mechanism is not easy to conduct the positive and negative poles of the battery and cause a short circuit risk, thereby improving the safety of the battery.

Specifically, 25%≤b1/b2≤35%. This arrangement can make the distance between the pressure relief mechanism and the terminal assembly sufficiently large, further reducing the risk of the pressure relief mechanism spraying onto the terminal assembly. In addition, the pressure relief mechanism and the terminal assembly are reasonably distributed on the end cover to avoid interference caused by the terminal assembly being too close to the edge of the end cover.

In some embodiments, the pressure relief mechanism is located at the geometric center of the figure formed by the outer contour of the end cap. By placing the pressure relief mechanism at the geometric center of the figure formed by the outer contour of the end cap, the distance between the pressure relief mechanism and the edge of the end cap is relatively short, and the exhaust path from the pressure relief mechanism in the battery is shorter overall, which is conducive to improving the pressure relief effect, avoiding the situation where the pressure relief is not timely due to the distance between the local position in the battery and the pressure relief mechanism being too far, and reducing the possibility of local explosion caused by untimely pressure relief.

In some embodiments, the end cap is provided with a liquid injection hole that penetrates along the thickness direction thereof. This arrangement facilitates liquid injection through the liquid injection hole during production, which is not only flexible in production, but also allows the number of liquid injections and the timing of liquid injections to be selected as needed. When insufficient electrolyte is detected, it can be replenished in time to reduce the battery defect rate.

Specifically, the injection hole is located between the terminal assembly and the pressure relief mechanism. The minimum distance between the injection hole and the pressure relief mechanism is b3, and the minimum distance between the injection hole and the terminal assembly is b4, and 1.5≤b3/b4≤2.

Among them, the injection hole is placed between the terminal assembly and the pressure relief mechanism, and the position of the injection hole will not be too close to the edge of the end cover. When the injection hole is injected, the infiltration path of the injected electrolyte to the surrounding areas is generally not much different, and the overall flow path of the electrolyte is short, which is conducive to the electrode assembly as a whole being fully immersed in the electrolyte and improving the overall injection effect. By limiting 1.5≤b3/b4≤2, the injection hole is set closer to the terminal assembly and farther from the pressure relief mechanism. Since the injection hole and the pressure relief mechanism are both weak areas on the end cover, keeping the injection hole and the pressure relief mechanism away can prevent the end cover from being easily deformed and cracked here. Moreover, the structure of the terminal assembly itself and other external components connected to the terminal assembly can strengthen the structural strength of the end cover at the terminal assembly. By setting the injection hole closer to the terminal assembly, the terminal assembly and other external components can be used to protect the injection hole, reducing the deformation of the end cover at the injection hole when subjected to pressure shock, thereby improving the overall structural strength.

In some embodiments, the terminal assembly is two and is respectively a positive terminal assembly and a negative terminal assembly, and the pressure relief mechanism is located between the two terminal assemblies. Thus, the battery end cap assembly can be connected to other external components (such as a converging member) for positive and negative electrodes, and the positive and negative electrodes are concentrated on the battery end cap assembly, which has a high degree of integration, and the overall battery routing and arrangement are more compact, which is conducive to reducing the overall occupied volume.

Specifically, the axis distance between the two terminal assemblies is D1, the minimum distance between the axis of the negative terminal assembly and the outer contour of the end cap is D2, and 5≤D1/D2≤7. After such arrangement, the two terminal assemblies can be reasonably distributed in the length direction of the end cap, and the structural strength of the end cap in the central area along the length direction can be appropriately improved, thereby reducing the deformation of the end cap at the center and improving the appearance and performance of the battery.

The energy storage device according to the second embodiment of the present application includes the battery end cover assembly described in the above embodiment.

According to the energy storage device of the second aspect of the present application, by obtaining a battery end cover assembly with an area that matches the pressure relief capacity, smooth explosion-proof pressure relief is ensured, while the structural strength of the battery end cover assembly is ensured, thereby improving the safety of the energy storage device.

The electrical equipment according to the third aspect of the present application includes the energy storage device described in the above embodiment.

According to the electrical equipment of the third aspect embodiment of the present application, by obtaining an energy storage device with a size that matches the pressure relief capacity, smooth explosion-proof pressure relief is ensured, while the structural strength of the battery end cover assembly is ensured, thereby improving the safety of the electrical equipment.

Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

FIG1 is a front view of a battery end cap assembly according to some embodiments;

FIG2 is a perspective view of a battery end cap assembly according to some embodiments;

FIG3 is an exploded view of a battery end cap assembly according to some embodiments;

FIG4 is a partial cross-sectional view of a battery end cap assembly according to some other embodiments;

FIG5 is a perspective view of an explosion-proof valve according to some embodiments;

FIG6 is a schematic diagram of explosion-proof valves and the locations of notched grooves thereon in some embodiments;

FIG. 7 is a schematic diagram of explosion-proof valves and the locations of notched grooves thereon in some other embodiments;

FIG8 is a cross-sectional view of an explosion-proof valve according to some embodiments;

FIG9 is a cross-sectional view of explosion-proof valves of other embodiments;

10 is a cross-sectional view of a battery end cap assembly at a terminal assembly according to some embodiments;

FIG11 is a perspective view of a battery cell according to some embodiments;

FIG12 is an exploded view of a battery cell according to some other embodiments;

FIG13 is a perspective view of a battery module according to some embodiments;

FIG14 is an exploded view of a battery pack according to some embodiments;

FIG. 15 is a schematic diagram of an electric device according to some embodiments.

Reference numerals:

Electrical equipment 01,

Energy storage device 01A,

Battery cell 1000, box 2000, battery module 1000B, battery pack 1000C,

Battery end cap assembly 100, housing 200, opening 200a, electrode assembly 300,

End cover 10, outer side 101, inner side 102, injection structure 11, injection hole 111, sealing nail 112, terminal lead hole 13, mounting hole 14, width median line L1,

Terminal assembly 20, electrode terminal 204, connector 205,

Positive terminal assembly 21, negative terminal assembly 22,

Explosion-proof patch 40,

Pressure relief mechanism 50, explosion-proof valve 51, opening area 511, predetermined opening boundary 512, connecting line 5121, notched groove 513, first notched section 5131, second notched section 5132, third notched section 5133,

Insulating plate 60 , first avoidance hole 61 , second avoidance hole 62 , and third avoidance hole 63 .

Detailed ways

The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

In the description of the present application, it should be understood that the terms "center", "length", "width", "thickness", "up", "down", "front", "back", "top", "bottom", "inside", "outside", "axial", "radial", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, "multiple" means two or more.

In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

The battery end cover assembly 100 according to an embodiment of the present application is described below with reference to the accompanying drawings.

1-3, a battery end cap assembly 100 according to an embodiment of the first aspect of the present application includes: an end cap 10, a terminal assembly 20 and a pressure relief mechanism 50, wherein the terminal assembly 20 and the pressure relief mechanism 50 are both disposed on the end cap 10. The end cap 10 is a sealing cover of the end of the battery, and the terminal assembly 20 is used for internal and external power transmission of the battery.

The pressure relief mechanism 50 is a component for releasing the internal pressure of the battery. The pressure relief mechanism 50 is arranged on the end cover 10. When the pressure or temperature inside the battery reaches a threshold, the pressure inside the battery is released through the pressure relief mechanism 50. The pressure relief mechanism 50 can be a component such as an explosion-proof valve 51, an explosion-proof disk, a pressure relief valve, a one-way valve, etc.

In some embodiments, the end cap 10 has a terminal lead-out hole 13 that penetrates along the thickness direction of the end cap 10, and the terminal assembly 20 is connected to the end cap 10 and covers the terminal lead-out hole 13. The terminal assembly 20 covers the terminal lead-out hole 13, which plays a role in sealing the terminal lead-out hole 13. Of course, in other embodiments of the present application, the terminal lead-out hole 13 may not be provided on the end cap 10, and the terminal assembly 20 is formed integrally on the end cap 10.

In some embodiments, the pressure relief mechanism 50 is located at the geometric center of the figure formed by the outer contour of the end cover 10. For example, in Figure 1, the end cover 10 is a rectangle, and the pressure relief mechanism 50 is located at the intersection of the diagonals of the rectangle. Here, the distances between the pressure relief mechanism 50 and the edge of the end cover 10 are relatively evenly distributed, and the exhaust path in the battery from the pressure relief mechanism 50 is shorter overall, which is beneficial to improving the pressure relief effect. This avoids the situation where the pressure relief is not timely due to the distance between a local position in the battery and the pressure relief mechanism 50 being too far, and reduces the possibility of local explosions caused by untimely pressure relief. In other embodiments of the present application, the pressure relief mechanism 50 may not be centered on the end cover 10. In this case, it is also necessary to reasonably set the distance between the pressure relief mechanism 50 and the edge of the end cover 10.

The graphic area formed by the outer contour of the end cover 10 is the first area S1, and the projection area of the pressure relief mechanism 50 on the end cover 10 is the second area S2, and the second area S2 accounts for 0.5%-5% of the first area S1. Taking the scheme shown in Figure 1 as an example, the end cover 10 is a rectangle, the length of the end cover 10 is b0, the width of the end cover 10 is e0, and the first area S1 of the outer contour of the end cover 10 is b0×e0. The projection of the pressure relief mechanism 50 on the end cover 10 is a runway shape, which includes a rectangle in the middle and semicircles at both ends. The length of the runway shape is b1 and the width is e1. The second area S2 of the runway shape is (b1-e1)×e1+π×(e1÷2) ^{^2} . At this time, the second area S2 is controlled between 0.5%-5% of the first area S1.

It is understandable that the pressure relief mechanism 50 is a weak area on the battery end cap assembly 100. The pressure relief mechanism 50 is provided with a thin wall (or a structure such as a notch or a flexible film), and when the pressure or temperature inside the battery reaches a threshold, the thin wall (or a structure such as a notch or a flexible film) is opened or torn to release the internal pressure and prevent the battery from bursting. Therefore, the area occupied by the pressure relief mechanism 50 on the end cap 10 can determine the pressure relief capacity and affect the overall structural strength of the battery end cap assembly 100.

In the present application, by limiting the second area S2 to account for no less than 0.5% of the first area S1, the area occupied by the pressure relief mechanism 50 will not be too small, and after the pressure relief mechanism 50 is opened, there is a sufficiently large pressure relief port for exhaust, so that the size of the battery end cover assembly 100 is more compatible with the pressure relief capacity. In this way, the probability of untimely pressure relief is reduced, and the battery safety is improved.

In the present application, by limiting the second area S2 to account for no more than 5% of the first area S1, the area occupied by the pressure relief mechanism 50 will not be too large, so that the overall structural strength of the battery end cover assembly 100 can be ensured, and it is not easy to deform after being under pressure. Moreover, since the area occupied by the pressure relief mechanism 50 is reduced, the edge of the end cover 10 at the pressure relief mechanism 50 is not easy to deform, thereby reducing the probability of the pressure relief mechanism 50 falling off and failing, and the reliability of the entire battery can be enhanced.

Optionally, the second area S2 may account for 0.8%, 1.0%, 1.2%, 1.3%, 1.5%, 1.7%, 2.1%, 2.3%, 2.5%, 2.8%, 3.0%, 3.4%, 3.7%, 3.9%, 4.1%, 4.3%, 4.5%, 4.8%, or 5.0% of the first area S1.

1 , a battery end cap assembly 100 according to an embodiment of the present application includes: an end cap 10, a terminal assembly 20 and a pressure relief mechanism 50, wherein the terminal assembly 20 and the pressure relief mechanism 50 are both arranged on the end cap 10. The pressure relief mechanism 50 and the terminal assembly 20 are spaced apart along the length direction of the end cap 10. The length of the pressure relief mechanism 50 along the length direction of the end cap 10 is b1, which is referred to as the length of the pressure relief mechanism 50, and the length b1 of the pressure relief mechanism 50 accounts for 5% to 12% of the length b0 of the end cap 10. The width of the pressure relief mechanism 50 along the width direction of the end cap 10 is e1, which is referred to as the width of the pressure relief mechanism 50, and the width e1 of the pressure relief mechanism 50 accounts for 15% to 25% of the width e0 of the end cap 10.

It is understandable that, since the pressure relief mechanism 50 is a weak area on the battery end cover assembly 100 , when the internal pressure of the battery is too high, the battery end cover assembly 100 will be squeezed, causing the battery end cover assembly 100 to be deformed to a certain extent.

By spacing the pressure relief mechanism 50 and the terminal assembly 20 along the length direction of the end cap 10, on the one hand, the terminal assembly 20 can avoid the pressure relief mechanism 50, and the concentrated stress at the terminal assembly 20 is relatively small when the internal pressure of the battery is high, thereby avoiding the loss of the terminal assembly 20 caused by excessive pressure, the connection falling off, etc. On the other hand, the length dimension of the end cap 10 can be used to space the pressure relief mechanism 50 and the terminal assembly 20 by a certain distance to avoid interference and influence between the two.

Among them, by controlling the ratio of the length b1 of the pressure relief mechanism 50 to the length b0 of the end cover 10 to be at least 5%, and the ratio of the width e1 of the pressure relief mechanism 50 to the width e0 of the end cover 10 to be at least 15%, the pressure relief mechanism 50 can occupy a sufficiently large area for pressure relief and exhaust, thereby ensuring smooth exhaust.

By controlling the ratio of the length b1 of the pressure relief mechanism 50 to the length b0 of the end cover 10 to not exceed 12%, a sufficient distance can be left on both sides of the pressure relief mechanism 50 on the end cover 10 to accommodate structures such as the terminal assembly 20. By controlling the ratio of the width e1 of the pressure relief mechanism 50 to the width e0 of the end cover 10 to not exceed 25%, the possibility of the end cover 10 being too narrow and easy to break on one side of the pressure relief mechanism 50 is reduced. The control of the length and width of the pressure relief mechanism 50 can ensure the exhaust and pressure relief capacity while ensuring the structural strength of the end cover 10, and prevent the end cover 10 from bending or breaking when subjected to impact or pressure.

After limiting the length b1 of the pressure relief mechanism 50, a certain space can be vacated on the end cover 10 to accommodate the terminal assembly 20, so that the pressure relief mechanism 50 and the terminal assembly 20 do not need to be arranged too close to each other, which may cause inconvenience in installation or even interfere with each other. In addition, limiting the length b1 of the pressure relief mechanism 50 can prevent the pressure relief mechanism 50 from being too long, resulting in excessive bending moment and excessive deformation, thereby preventing the pressure relief mechanism 50 from being easily detached due to excessive deformation. In this way, the pressure relief mechanism 50 is also prevented from being ejected from the end cover 10 by high-pressure gas under high pressure, resulting in the exhaust direction being unable to be limited and the exhaust being hindered by the detached pressure relief mechanism 50.

In some embodiments, the area ratio of the pressure relief mechanism 50 on the end cover 10 (i.e., the ratio of the second area S2 to the first area S1) is 0.5%-5%, the length ratio of the pressure relief mechanism 50 on the end cover 10 (i.e., the ratio of the length b1 to the length b0) is 5%-12%, and the width ratio of the pressure relief mechanism 50 on the end cover 10 (i.e., the ratio of the width e1 to the width e0) is 15%-25%, so that the pressure relief mechanism 50 can occupy a large enough area for pressure relief and exhaust, ensuring smooth and timely exhaust. At the same time, the pressure relief mechanism 50 on each side of the end cover 10 does not need to be set too narrow, avoiding the risk of the edge of the end cover 10 being easily broken due to the pressure relief mechanism 50 being too long or too wide, and avoiding the end cover 10 from bending or breaking when it is impacted or under pressure. In addition, there is enough space on the end cover 10 for the components to be arranged, so that the components can be spaced apart without interfering with each other. In addition, the structural strength of the end cover 10 can be ensured, the end cover 10 can be prevented from being deformed too much when under pressure, and the possibility of gas being exhausted from the edge of the end cover 10 when the temperature or pressure in the battery is too high can be avoided. It can ensure that the gas is exhausted only from the pressure relief mechanism 50, and the exhaust direction of the gas inside the battery can be effectively controlled, so that the post-processing of the discharged electrolyte or high-temperature gas can be facilitated, and unnecessary corrosion, fire, etc. can be avoided due to arbitrary discharge of electrolyte or high-temperature gas in the battery.

Optionally, the ratio of the length b1 of the pressure relief mechanism 50 to the length b0 of the end cover 10 is 5%, 7%, 9%, 10%, 11.5%, 12%, etc.

Optionally, the ratio of the width e1 of the pressure relief mechanism 50 to the width e0 of the end cover 10 is 15%, 17%, 19%, 20%, 21.5%, 22.4%, 23.7%, 24.8%, 25%, etc.

According to the battery end cap assembly 100 of the embodiment of the present application, it includes: an end cap 10, a terminal assembly 20 and a pressure relief mechanism 50, and the terminal assembly 20 and the pressure relief mechanism 50 are both arranged on the end cap 10. As shown in FIG1, the length of the pressure relief mechanism 50 along the length direction of the end cap 10 is length b1, and the minimum spacing between the pressure relief mechanism 50 and the terminal assembly 20 is b2, b2>b1. In this way, the terminal assembly 20 and other external components connected to the terminal assembly 20 can be separated from the terminal assembly 20 by a sufficient distance. After the pressure relief mechanism 50 is opened, other external components are not easy to block the pressure relief mechanism 50, which can reduce the probability of internal gas and electrolyte spraying onto the terminal assembly 20 and other external components when the pressure relief mechanism 50 is released, and reduce the possibility of fire in other external components. Moreover, after the pressure relief mechanism 50 is separated from the terminal assembly 20 by a safe distance, the spray of the pressure relief mechanism 50 is not easy to conduct the positive and negative poles of the battery and generate a short circuit risk, thereby improving the safety of the battery.

Optionally, the minimum spacing between the pressure relief mechanism 50 and the terminal assembly 20 is b2, the length of the pressure relief mechanism 50 is b1, and 25%≤b1/b2≤35%. This arrangement can make the spacing between the pressure relief mechanism 50 and the terminal assembly 20 sufficiently large, further reducing the risk of the ejection of the pressure relief mechanism 50 being ejected onto the terminal assembly 20. In addition, the pressure relief mechanism 50 and the terminal assembly 20 are reasonably distributed on the end cover 10 to avoid interference caused by the terminal assembly 20 being too close to the edge of the end cover 10.

The terminal assembly 20 is closer to the edge of the end cover 10 relative to the pressure relief mechanism 50. Since the edge of the end cover 10 is supported, the support provided by the edge of the end cover 10 can be used to strengthen the structural strength of the terminal assembly 20, thereby reducing the pressure on the terminal assembly 20 when the battery end cover assembly 100 is under pressure, thereby reducing the probability of damage or falling off of the terminal assembly 20.

Further optionally, b1/b2 can be 25%, 27.1%, 29.6%, 31.2%, 33.1%, 34.5%, 35%, etc.

1 , a battery end cap assembly 100 according to an embodiment of the present application includes: an end cap 10, a terminal assembly 20 and a pressure relief mechanism 50, wherein the terminal assembly 20 and the pressure relief mechanism 50 are both disposed on the end cap 10. As shown in FIGS. 4 and 5 , the pressure relief mechanism 50 includes an explosion-proof valve 51, and the explosion-proof valve 51 includes an opening area 511. For the convenience of description, the outer edge of the opening area 511 is referred to as a predetermined opening boundary 512.

The opening area 511 is an area reserved for pressure relief when designing the explosion-proof valve 51. When the temperature or pressure inside the battery increases and pressure relief is required, the opening area 511 is opened to form a pressure relief port on the explosion-proof valve 51, and the gas inside the battery is discharged from the pressure relief port after the opening area 511 is opened. The predetermined opening boundary 512 is the edge contour of the pressure relief port formed after the opening area 511 is opened.

Specifically, the area of the opening area 511 accounts for at least half of the area of the explosion-proof valve 51 (i.e., the second area S2), and a sufficiently large pressure relief port is obtained after the opening area 511 is opened. The area of the opening area 511 is reasonably set to ensure the pressure relief capacity of the explosion-proof valve 51.

Furthermore, the area of the opening zone 511 does not exceed 95% of the area of the explosion-proof valve 51, leaving enough margin for fixing or connecting the explosion-proof valve 51, so that the explosion-proof valve 51 is not easy to fall off, thereby improving the working reliability of the explosion-proof valve 51.

The explosion-proof valve 51 is used for pressure relief. Compared with the pressure relief valve, one-way valve and other components, the explosion-proof valve 51 is thinner and does not require too much space for the pressure relief mechanism 50, which is conducive to improving the density of the internal structure of the battery, thereby helping to improve the energy density of the battery. After the internal structure of the battery is tightly arranged, it is also conducive to improving the structural strength. Moreover, in some embodiments, the inner side 102 of the end cover 10 (the surface of the end cover 10 facing the inside of the battery) is connected to an insulating plate 60, and the insulating plate 60 does not need to leave too much space corresponding to the explosion-proof valve 51, so that the insulating plate 60 can provide greater support for the end cover 10, reducing the degree of deformation of the battery end cover assembly 100 after being subjected to force.

In some embodiments, the tensile strength of the explosion-proof valve 51 is 90-130N/mm ^{^2} , so as to avoid the explosion-proof valve 51 being opened before the internal pressure or temperature reaches the threshold due to the tensile strength being too low, and the explosion-proof valve 51 being difficult to open and the exhaust being not timely due to the tensile strength being too high. Therefore, the reasonable setting of the tensile strength of the explosion-proof valve 51 is helpful to improve the reliability and stability of its performance.

Specifically, the tensile strength of the explosion-proof valve 51 is within the range of 90-130N/mm ^{^2} , and the explosion-proof valve 51 can withstand a pressure of approximately 0.4-0.8Mpa. Therefore, the tensile strength of the explosion-proof valve 51 should not be lower than 90N/mm ^{^2} , so as to avoid the explosion-proof valve 51 from being able to withstand a pressure far lower than 0.4Mpa, and to avoid the explosion-proof valve 51 from being broken due to temporary local heating or pressure increase inside the battery, so that the explosion-proof valve 51 will not be damaged under reasonable temperature or pressure changes, and the failure rate of the explosion-proof valve 51 will be reduced. The tensile strength of the explosion-proof valve 51 should not be higher than 130N/mm ^{^2} , so as to avoid the explosion-proof valve 51 from being able to withstand a pressure far higher than 0.8Mpa, and to avoid the explosion-proof valve 51 from being broken when there is an explosion risk inside the battery, and to ensure that the explosion-proof valve 51 can be opened in time to exhaust. Selecting a suitable tensile strength for the explosion-proof valve 51 makes it difficult for the explosion-proof valve 51 to be damaged during processing and assembly, thereby reducing the production defect rate of the battery end cover assembly.

Optionally, the tensile strength of the explosion-proof valve 51 is 90, 95, 100, 103, 108, 112, 116, 121, 128, 130, etc. (unit: N/mm ^{^2} ). Further optionally, the tensile strength of the explosion-proof valve 51 is 110N/mm ^{^2} .

In some embodiments, as shown in Figures 4 to 6, the explosion-proof valve 51 is provided with a notch groove 513, and the explosion-proof valve 51 is thinnest at the notch groove 513, which is conducive to timely pressure relief and exhaust. Of course, the present application is not limited to this, and the opening area 511 can also be set as a thin wall as a whole, which can be torn at any place of the thin wall when subjected to pressure shock.

In the present application, the number of notched grooves 513 on the explosion-proof valve 51 may be one or more. When there are more than one notched grooves 513 on the explosion-proof valve 51, the more than one notched grooves 513 may be at least partially connected, or the more than one notched grooves 513 may be spaced apart, which is not limited here. In the example of FIG. 6, a C-shaped notched groove 513 is provided on the explosion-proof valve 51. As in the example of FIG. 7, two spaced-apart C-shaped notched grooves 513 are provided on the explosion-proof valve 51. The shape of each notched groove 513 may also be referred to as a runway shape, and the explosion-proof valve 51 of FIG. 7 may also be referred to as a double runway type explosion-proof valve. In other examples, two C-shaped notched grooves 513 are provided on the explosion-proof valve 51, and the two notched grooves 513 are symmetrically arranged, and this explosion-proof valve 51 may also be referred to as a double C-type explosion-proof valve.

In some embodiments, as shown in FIG8 and FIG9, the minimum thickness of the explosion-proof valve 51 at the notch groove 513 is the first thickness n1, the thickness of the opening area 511 is n2, and n1 is 15% to 25% of n2. Here, the thickness ratio of the explosion-proof valve 51 at the notch groove 513 and the opening area 511 is limited, and while the explosion-proof valve 51 is thinner at the notch groove 513, the thickness of the opening area 511 will not be too thick. The thickness of the explosion-proof valve 51 at the notch groove 513 is thinner, so that the explosion-proof valve 51 can be broken in time at the notch groove 513 when the internal pressure or temperature of the battery reaches the threshold. The thickness of the opening area 511 will not be too thick, so that the opening area 511 can be easily opened by the high-pressure gas after the notch groove 513 is broken, so that the pressure relief port can be fully opened and the exhaust can be smooth. By limiting the thickness of the explosion-proof valve 51 in the opening area 511 to be at least four times the thickness at the notched groove 513, when the explosion-proof valve 51 is subjected to internal pressure shock or the temperature is too high, the pressure can be concentrated at the notched groove 513, and the explosion-proof valve 51 breaks open at the notched groove 513, which makes the exhaust more timely and helps to improve the working sensitivity of the explosion-proof valve 51.

Optionally, the ratio of n1 to n2 may be 15%, 17%, 20%, 23%, 25%, etc.

In some embodiments, as shown in Figures 6 and 7, the projection area of the notch groove 513 on the end cover 10 is a third area S3, and the third area S3 accounts for 1.0% to 1.5% of the second area S2. The second area S2 is the projection area of the explosion-proof valve 51 on the end cover 10.

In the scheme shown in FIG6, the projection of the explosion-proof valve 51 on the end cover 10 is a runway shape, and the area occupied by the runway shape is the second area S2. The projection of the notched groove 513 on the end cover 10 is a C-shaped strip in the shaded part of FIG6, and the area of the shaded area is the third area S3. In the scheme shown in FIG7, the projection of the explosion-proof valve 51 on the end cover 10 is a runway shape, and the area occupied by the runway shape is the second area S2. There are two notched grooves 513, and the projection on the end cover 10 is two C-shaped strips shown in the shaded part of FIG7, and the areas of the two C-shaped strips are S31 and S32 respectively, and the area of the shaded area is the third area S3=S31+S32.

Here, the third area S3 is limited to 1.0% to 1.5% of the second area S2, that is, the area occupied by the weakest area on the explosion-proof valve 51 is limited. Among them, the third area S3 cannot be too small in proportion to the second area S2, so that when the pressure or temperature inside the battery reaches the threshold, more area at the notched groove 513 can sense the pressure or temperature change, thereby breaking and releasing the pressure in time, thereby improving the working sensitivity of the explosion-proof valve 51.

Limiting the proportion of the third area S3 to the second area S2 does not affect the timely breaking of the explosion-proof valve 51 when the internal pressure or temperature of the battery changes. However, the smaller third area S3 can effectively avoid the external impact force acting on the notch groove 513, thereby preventing the explosion-proof valve 51 from breaking when the battery end cover assembly 100 is accidentally bumped, thereby improving the working stability of the explosion-proof valve 51.

When the pressure relief mechanism 50 is placed at the geometric center of the figure formed by the outer contour of the end cover 10, the end cover 10 will be deformed when the internal pressure of the battery is too high or the temperature is too high. The geometric center of the end cover 10 is far away from the edge of the end cover 10 and therefore has a larger deformation amount, so that the explosion-proof valve 51 can timely sense the change in deformation amount caused by the change in internal pressure, and the notched groove 513 on the explosion-proof valve 51 can quickly and timely break open the exhaust.

Optionally, the proportion of the third area S3 to the second area S2 may be 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, etc.

In some specific embodiments, the notched groove 513 is located in the opening area 511. In some optional embodiments, the notched groove 513 is located on the predetermined opening boundary 512, that is, the notched groove 513 is arranged along the predetermined opening boundary 512. For example, when the predetermined opening boundary 512 is a rectangular line, the rectangular area surrounded by the predetermined opening boundary 512 is the opening area 511, and the notched groove 513 is arranged along the rectangular line. When the explosion-proof valve 51 is ruptured at the notched groove 513 under pressure, a rectangular pressure relief port can be formed. At this time, the torn opening area 511 can be completely separated from the rest of the explosion-proof valve 51, or it can be connected to the rest of the part on one side.

In some other optional embodiments, the notched groove 513 may not be arranged along the predetermined opening boundary 512. For example, when the predetermined opening boundary 512 is a rectangular line, the rectangular area surrounded by the predetermined opening boundary 512 is the opening area 511, and the notched groove 513 is arranged along the diagonal line of the opening area 511. When the explosion-proof valve 51 is ruptured at the notched groove 513 due to pressure, the opening area 511 can be torn into four triangular areas along the diagonal line. After the opening area 511 is opened, the pressure relief port formed is rectangular.

Optionally, the notched groove 513 may be partially arranged along the predetermined opening boundary 512, and partially arranged in the opening area 511. Therefore, the arrangement shape of the notched groove 513 is very flexible.

Taking the scheme shown in FIG. 5 as an example, the notched groove 513 includes two first notched segments 5131 arranged opposite to each other and in an arc shape, a second notched segment 5132 in a straight line shape, and two third notched segments 5133 arranged at intervals and in a straight line shape. The second notched segment 5132 is arranged in parallel with the third notched segment 5133. The two ends of the second notched segment 5132 are respectively connected to the two first notched segments 5131, and each third notched segment 5133 is connected to the corresponding first notched segment 5131. The first notched segment 5131, the second notched segment 5132 and the third notched segment 5133 are located on the predetermined opening boundary 512, and the portion of the predetermined opening boundary 512 located between the two third notched segments 5133 is the connecting line 5121.

That is, the second notch segment 5132 connects one end of the two first notch segments 5131, and the other ends of the two first notch segments 5131 are respectively connected to a third notch segment 5133, and the two third notch segments 5133 are arranged at an interval. There is a connecting line 5121 between the two third notch segments 5133, and the connecting line 5121 and the outer edge of the orthographic projection of the notch groove 513 together constitute the predetermined opening boundary 512.

After such arrangement, when the opening area 511 is opened, it will remain connected at the connecting line 5121 part, preventing the opening area 511 from being completely separated from the rest after being opened. Especially when pressure relief is required, electrolyte or the like may stick to the opening area 511, and even in case of an accident causing a fire, by connecting the opening area 511 to the end cover 10, the burning opening area 511 is prevented from bursting out, thereby reducing the probability of the fire spreading outward.

In some embodiments, as shown in FIG. 4 , a notched groove 513 is provided on the explosion-proof valve 51. As shown in FIG. 8 and FIG. 9 , the minimum thickness of the explosion-proof valve 51 at the notched groove 513 is the first thickness n1, and the first thickness n1 is 0.04-0.06 mm. With such a configuration, the sensitivity of the explosion-proof valve 51 can be further improved and the safety can be improved. After the range of the first thickness n1 is limited here, the explosion-proof valve 51 can be limited to have a suitable withstand voltage value, and can be broken in time to exhaust when the temperature or pressure inside the battery is too high. Limiting the range of the arc radius r1 is conducive to the uniform distribution of the internal stress of the explosion-proof valve 51 on the wall surface of the notched groove 513 along the arc line, which greatly reduces the internal stress difference at various points along the arc line. In this way, when the internal pressure or temperature of the battery changes and causes the explosion-proof valve 51 to deform, the explosion-proof valve 51 breaks open due to deformation at the notched groove 513. At this time, the explosion-proof valve 51 breaks at the notched groove 513 mainly due to the changes in internal temperature and pressure, and the influence of concentrated internal stress is reduced, so that the actual pressure resistance value of the explosion-proof valve 51 is more accurate.

Specifically, the tensile strength of the explosion-proof valve 51 is 90-130 N/mm ^{^2} , and the first thickness n1 is 0.04-0.06 mm, which can enable the exhaust pressure of the battery by the explosion-proof valve 51 to reach a suitable threshold.

In some embodiments, as shown in FIG4 , a notched groove 513 is provided on the explosion-proof valve 51. As shown in FIG8 and FIG9 , the contour line of the notched groove 513 on the cross section perpendicular to the extension direction of the notched groove 513 is U-shaped or C-shaped. Of course, the present application scheme does not exclude that in some schemes, the contour line of the notched groove 513 on the cross section perpendicular to the extension direction of the notched groove 513 is a rectangle or a triangle or other polygon. But relatively speaking, the U-shaped or C-shaped cross section reduces the sharp corners of the contour of the notched groove 513, avoiding excessive concentrated stress at the weakest point of the explosion-proof valve 51, thereby avoiding the possibility of the explosion-proof valve 51 breaking at a large sharp corner due to excessive concentrated internal stress. Therefore, such a setting can improve the reliability of the operation of the explosion-proof valve 51.

As for the production of explosion-proof valve 51, cutting or stamping is usually used to form notch groove 513. Since the contour line of notch groove 513 on the cross section perpendicular to the extension direction of notch groove 513 is U-shaped or C-shaped, sharp corner design is avoided, which avoids excessive burrs caused by sharp corners during processing and the possibility of sharp corners being torn due to pulling burrs during production, thereby avoiding a reduction in the pressure resistance value of explosion-proof valve 51.

Specifically, the contour line of the notched groove 513 on the cross section perpendicular to the extension direction of the notched groove 513 includes an arc line, and the radius r1 of the arc line is 0.05-0.15 mm. The radius r1 of the arc line is limited to at least 0.05 mm, which, on the one hand, facilitates the easy processing of the arc profile here, and on the other hand, effectively reduces the concentrated stress generated here. The radius r1 of the arc line is limited to no more than 0.15 mm, so that the depth of the notched groove 513 and the minimum thickness of the explosion-proof valve 51 at the notched groove 513 can be reasonably distributed.

Optionally, the radius r1 of the arc line may be 0.05, 0.07, 0.09, 0.10, 0.12, 0.13, 0.15 mm, etc.

Specifically, the minimum thickness of the explosion-proof valve 51 at the notch groove 513 is the first thickness n1, and the first thickness n1 is 0.04-0.06 mm. The contour line of the notch groove 513 on the cross section perpendicular to the extension direction of the notch groove 513 includes an arc line, and the radius r1 of the arc line is 0.05-0.15 mm. This is conducive to increasing the exhaust pressure of the explosion-proof valve 51 to the exhaust pressure or temperature threshold required by the battery.

In the present application, the explosion-proof valve 51 is arranged in a flexible manner. For example, the explosion-proof valve 51 can be formed integrally on the end cover 10, for example, by punching a notch groove 513 on the end cover 10, the end cover 10 is easily depressurized at this point, thereby forming the explosion-proof valve 51. In this way, the number of parts of the battery end cover assembly 100 is small during processing, and the production efficiency is higher.

For another example, as shown in Figures 3 and 4, the end cover 10 is provided with a mounting hole 14, and the explosion-proof valve 51 is connected to the end cover 10 and covers the mounting hole 14. In this structure, the size of the explosion-proof valve 51 is relatively flexible, and the explosion-proof valve 51 of a suitable thickness can be selected as needed to obtain a more matched pressure relief capacity.

In some embodiments, as shown in FIG. 3 , the battery end cover assembly 100 further includes: an explosion-proof patch 40 , which is attached to the outer surface of the end cover 10 and covers the pressure relief mechanism 50 .

The explosion-proof patch 40 can be constructed as an insulating member and has a certain structural strength. By providing the explosion-proof patch 40, the leakage of the pressure relief mechanism 50 can be reduced. Moreover, by observing whether the explosion-proof patch 40 is bulging, it is possible to quickly check whether the pressure relief mechanism 50 is in a venting state. Or when not in normal use, by observing whether the explosion-proof patch 40 is bulging, it is possible to check whether the pressure relief mechanism 50 is ineffective.

1 to 3, a battery end cap assembly 100 according to an embodiment of the present application includes: an end cap 10 and a liquid injection structure 11 disposed on the end cap 10. The end cap 10 is an end sealing cap of the battery. The liquid injection structure 11 is disposed on the end cap 10, and electrolyte can be injected into the battery through the liquid injection structure 11. After the electrolyte injection is completed, the end cap 10 is sealed through the liquid injection structure 11.

In some embodiments, as shown in FIG3 , the end cap 10 is provided with an injection hole 111 that penetrates along the thickness direction thereof, and the battery end cap assembly 100 further includes a sealing nail 112, which is connected to the end cap 10 and covers the injection hole 111. This arrangement facilitates the injection of liquid through the injection hole 111 during production, which is not only flexible in production, but also allows the number of injections and the timing of injections to be selected as needed. When the electrolyte is found to be insufficient during detection, it can be replenished in time to reduce the defective rate of the battery. When production is completed, it is sealed by the sealing nail 112 to improve the sealing performance.

Specifically, the figure formed by the outer contour of the end cap 10 has a width median line L1, and the width median line L1 is equidistant from the two opposite sides of the end cap 10. The injection hole 111 is located on the width median line L1. In this way, when the injection hole 111 is injected, the infiltration path of the injected electrolyte to both sides is substantially consistent, and the overall flow path of the electrolyte is shorter, which is conducive to the electrode assemblies 300 on both sides being fully immersed in the electrolyte, thereby improving the overall injection effect.

Further, as shown in Fig. 1, the injection hole 111 is located between the terminal assembly 20 and the pressure relief mechanism 50. Here, the position of the injection hole 111 is not too biased, so that the electrolyte can be quickly dispersed and flowed during injection.

Optionally, the minimum spacing between the injection hole 111 and the pressure relief mechanism 50 is b3, and the minimum spacing between the injection hole 111 and the terminal assembly 20 is b4, and 1.5≤b3/b4≤2. It can be understood that the structure of the end cover 10 at the injection hole 111 is relatively weak. By setting the injection hole 111 closer to the terminal assembly 20 and farther from the pressure relief mechanism 50, on the one hand, the injection hole 111 and the injection hole 111 are too close to each other, which causes the end cover 10 to be easily deformed at this place. On the other hand, the structural strength of the terminal assembly 20 is used to form a certain protection for the injection hole 111, thereby reducing the deformation of the end cover 10 at the injection hole 111 when subjected to pressure shock, thereby improving the overall structural strength.

In some embodiments, as shown in FIG. 1 and FIG. 2 , a battery end cap assembly 100 includes: an end cap 10, a terminal assembly 20, and a pressure relief mechanism 50. The terminal assembly 20 and the pressure relief mechanism 50 are arranged on the end cap 10, and a liquid injection structure 11 is provided on the end cap 10. The terminal assembly 20, the liquid injection structure 11, and the pressure relief mechanism 50 are arranged at intervals along the length direction of the end cap 10. The figure formed by the outer contour of the end cap 10 has a width median line L1, and the terminal assembly 20 and the pressure relief mechanism 50 are arranged at intervals on the width median line L1.

Among them, the distances between the terminal assembly 20 and the two sides of the end cover 10 are generally consistent. When connected to other external components (such as a conduit component), the connection position of the two is set in the center of the end cover 10, and the connection position does not protrude too much to the edge, which is beneficial to protect the connection reliability of the connection. Especially when there is an external impact, the impact force is not easily transmitted to the connection between the terminal assembly 20 and other external components. The pressure relief mechanism 50 is also set on the width median line L1. The resistance encountered by the pressure relief mechanism 50 when releasing pressure to both sides is also generally balanced, which is conducive to smoother pressure relief.

3 and 10, the battery end cap assembly 100 according to the embodiment of the present application includes: an end cap 10, a terminal assembly 20, a pressure relief mechanism 50 and an insulating plate 60, wherein the terminal assembly 20 and the pressure relief mechanism 50 are both disposed on the end cap 10. The end cap 10 has an outer side surface 101 and an inner side surface 102 opposite to each other along its thickness direction, and the insulating plate 60 is connected to the inner side surface 102 of the end cap 10.

It is understandable that the inner side surface 102 of the end cap 10 refers to the surface on the end cap 10 facing the inside of the battery. That is, the electrode assembly 300 is arranged in the battery end cap assembly 100, and the inner side surface 102 of the end cap 10 is arranged toward the electrode assembly 300. The insulating plate 60 is a component that separates the end cap 10 from the electrode assembly 300. The insulating plate 60 is arranged on the side of the end cap 10 facing the electrode assembly 300, and the end cap 10 and the electrode assembly 300 are insulated and isolated by the insulating plate 60. The insulating plate 60 is an insulating material, and the insulating plate 60 can be a material such as plastic, rubber, etc. Moreover, after the battery end cap assembly 100 includes the insulating plate 60, the end cap 10 is supported by the insulating plate 60, and the overall structural strength is improved, and it is not easy to deform or damage.

Specifically, as shown in FIG3 , the insulating plate 60 is provided with a first avoidance hole 61 corresponding to the terminal assembly 20, and the insulating plate 60 is provided with a second avoidance hole 62 corresponding to the pressure relief mechanism 50. Thus, the first avoidance hole 61 can facilitate the electrical connection between the terminal assembly 20 and the internal electrode assembly 300, and the second avoidance hole 62 facilitates the gas to rush to the pressure relief mechanism 50 through the second avoidance hole 62 when the gas is exhausted inside the battery.

In some specific embodiments, as shown in FIG3 , the end cap 10 is provided with an injection hole 111 that penetrates along the thickness direction thereof, the battery end cap assembly 100 further includes a sealing nail 112, the sealing nail 112 is connected to the end cap 10 and covers the injection hole 111, and the insulating plate 60 is provided with a third avoidance hole 63 corresponding to the injection hole 111. This is so that during injection, the electrolyte can flow smoothly from the injection hole 111 and flow to the electrode assembly 300 through the third avoidance hole 63. During injection, the insulating plate 60 has less interference, the electrolyte flows more smoothly, and the injection efficiency can be improved. In addition, after the size and orientation of the third avoidance hole 63 are reasonably set, the flow direction of the electrolyte can also be guided.

1-3 , a battery end cap assembly 100 according to an embodiment of the present application includes: an end cap 10 , a terminal assembly 20 and a pressure relief mechanism 50 , wherein the terminal assembly 20 and the pressure relief mechanism 50 are both disposed on the end cap 10 .

As shown in Fig. 10, the terminal assembly 20 may include an electrode terminal 204 and a connector 205. The connector 205 is a component for fixing the electrode terminal 204 to the end cap 10. The electrode terminal 204 is a component for outputting the electric energy of the battery. The terminal assembly 20 on the end cap 10 may be one or two.

In some embodiments, as shown in FIG2 , the terminal assembly 20 is two and is respectively a positive terminal assembly 21 and a negative terminal assembly 22, and the pressure relief mechanism 50 is located between the two terminal assemblies 20. Thus, the battery end cap assembly 100 can be connected to other external components (such as a current collecting member) for positive and negative electrodes, and the positive and negative electrodes are concentrated on the battery end cap assembly 100, with high integration, and the overall routing and arrangement of the battery are more compact, which is conducive to reducing the overall occupied volume.

Specifically, as shown in FIG1 , the axial distance between the two terminal assemblies 20 is D1, the minimum distance between the axis of the negative terminal assembly 22 and the outer contour of the end cap 10 is D2, and 5≤D1/D2≤7. After such arrangement, the two terminal assemblies 20 can be reasonably distributed in the length direction of the end cap 10, and the structural strength of the end cap 10 in the central area along the length direction can be improved, thereby reducing the deformation of the end cap 10 at the center, and improving the appearance and performance of the battery.

1-3 , a battery end cap assembly 100 according to an embodiment of the first aspect of the present application includes: an end cap 10, a terminal assembly 20 and a pressure relief mechanism 50. The terminal assembly 20 and the pressure relief mechanism 50 are both arranged on the end cap 10. The terminal assembly 20 is used for internal and external electrical energy transmission of the battery. The pressure relief mechanism 50 is a component for releasing the internal pressure of the battery.

The pressure relief mechanism 50 and the terminal assembly 20 are spaced apart along the length direction of the end cover 10. The graphic area formed by the outer contour of the end cover 10 is the first area S1, and the projection area of the pressure relief mechanism 50 on the end cover 10 is the second area S2, and the second area S2 accounts for 0.5%-5% of the first area S1. The pressure relief mechanism 50 and the terminal assembly 20 are spaced apart along the length direction of the end cover 10. The dimension of the pressure relief mechanism 50 along the length direction of the end cover 10 is b1, which is called the length of the pressure relief mechanism 50, and the ratio of the length b1 of the pressure relief mechanism 50 to the length b0 of the end cover 10 is 5% to 12%. The dimension of the pressure relief mechanism 50 along the width direction of the end cover 10 is e1, which is called the width of the pressure relief mechanism 50, and the ratio of the width e1 of the pressure relief mechanism 50 to the width e0 of the end cover 10 is 15% to 25%. As a result, the pressure relief mechanism 50 can occupy a large enough area for pressure relief and exhaust, ensuring smooth and timely exhaust.

At the same time, the end cap 10 does not need to be set too narrow on each side of the pressure relief mechanism 50, so as to avoid the risk of the edge of the end cap 10 being easily broken due to the pressure relief mechanism 50 being too long or too wide, and to avoid the end cap 10 being bent or broken when subjected to impact or pressure. Moreover, there is enough space for the components on the end cap 10 to be arranged, so that the components can be spaced apart without interfering with each other. In addition, the structural strength of the end cap 10 can be guaranteed, the deformation of the end cap 10 when it is under pressure can be avoided, and the possibility of gas exhausting from the edge of the end cap 10 when the temperature or pressure in the battery is too high can be avoided. It is ensured that the gas is exhausted only from the pressure relief mechanism 50, and the exhaust direction of the gas inside the battery can be effectively controlled, so as to facilitate the post-processing of the discharged electrolyte or high-temperature gas, and avoid the arbitrary discharge of electrolyte or high-temperature gas in the battery to cause unnecessary corrosion, fire, etc.

As shown in FIG1 , the dimension of the pressure relief mechanism 50 along the length direction of the end cap 10 is length b1, and the minimum spacing between the pressure relief mechanism 50 and the terminal assembly 20 is b2, b2>b1. In this way, the terminal assembly 20 and other external components connected to the terminal assembly 20 can be separated from the terminal assembly 20 by a sufficient distance. After the pressure relief mechanism 50 is opened, other external components are not easy to block the pressure relief mechanism 50, which can reduce the probability of internal gas and electrolyte spraying onto the terminal assembly 20 and other external components when the pressure relief mechanism 50 releases pressure, and reduce the possibility of fire in other external components. Moreover, after the pressure relief mechanism 50 is separated from the terminal assembly 20 by a safe distance, the ejection of the pressure relief mechanism 50 is not easy to conduct the positive and negative poles of the battery and cause a short circuit risk, thereby improving the safety of the battery.

Optionally, the minimum spacing between the pressure relief mechanism 50 and the terminal assembly 20 is b2, the length of the pressure relief mechanism 50 is b1, and 25%≤b1/b2≤35%. This arrangement can make the spacing between the pressure relief mechanism 50 and the terminal assembly 20 sufficiently large, further reducing the risk of the ejection of the pressure relief mechanism 50 onto the terminal assembly 20. In addition, the pressure relief mechanism 50 and the terminal assembly 20 are reasonably distributed on the end cover 10 to avoid interference caused by the terminal assembly 20 being too close to the edge of the end cover 10.

In some embodiments, as shown in FIG. 4 and FIG. 5 , the pressure relief mechanism 50 includes an explosion-proof valve 51, and the explosion-proof valve 51 includes an opening area 511. The opening area 511 is an area reserved for pressure relief when designing the explosion-proof valve 51. When the temperature or pressure inside the battery increases and pressure relief is required, the opening area 511 is opened to form a pressure relief port on the explosion-proof valve 51, and the gas inside the battery is discharged from the pressure relief port after the opening area 511 is opened. For the convenience of description, the outer edge of the opening area 511 is referred to as the predetermined opening boundary 512, and the predetermined opening boundary 512 is the edge contour of the pressure relief port formed after the opening area 511 is opened.

As shown in Figures 4 to 6, the explosion-proof valve 51 is provided with a notch groove 513, and the explosion-proof valve 51 is thinnest at the notch groove 513, which is conducive to timely pressure relief and exhaust. Of course, the present application is not limited to this, and the opening area 511 can also be set as a thin wall as a whole, which can be torn at any place of the thin wall when subjected to pressure shock.

In some embodiments, as shown in FIG8 and FIG9, the minimum thickness of the explosion-proof valve 51 at the notch groove 513 is the first thickness n1, the thickness of the opening area 511 is n2, and n1 is 15% to 25% of n2. Here, the thickness ratio of the explosion-proof valve 51 at the notch groove 513 and the opening area 511 is limited, and while the explosion-proof valve 51 at the notch groove 513 is thinner, the thickness of the opening area 511 will not be too thick. The thickness of the explosion-proof valve 51 at the notch groove 513 is thinner, so that the explosion-proof valve 51 at the notch groove 513 can be broken in time when the internal pressure or temperature of the battery reaches the threshold. The thickness of the opening area 511 will not be too thick, so that the opening area 511 can be easily opened by the high-pressure gas after the notch groove 513 is broken, so that the pressure relief port can be fully opened and the exhaust can be smooth. By limiting the thickness of the explosion-proof valve 51 in the opening area 511 to be at least four times the thickness at the notched groove 513, when the explosion-proof valve 51 is subjected to internal pressure shock or the temperature is too high, the pressure can be concentrated at the notched groove 513, and the explosion-proof valve 51 breaks open at the notched groove 513, which makes the exhaust more timely and helps to improve the working sensitivity of the explosion-proof valve 51.

Optionally, the ratio of n1 to n2 may be 15%, 17%, 20%, 23%, 25%, etc.

In some specific embodiments, as shown in FIG8 and FIG9 , the cross section of the notched groove 513 perpendicular to the extension direction of the notched groove 513 is U-shaped or C-shaped. The U-shaped or C-shaped cross section reduces the sharp corners of the profile of the notched groove 513, thereby avoiding excessive concentrated stress at the weakest point of the explosion-proof valve 51, thereby avoiding the possibility of the explosion-proof valve 51 breaking at a large sharp corner due to excessive concentrated internal stress. Therefore, such a setting can improve the reliability of the explosion-proof valve 51.

The energy storage device 01A according to the second embodiment of the present application includes the battery end cap assembly 100 described in the above embodiment. The energy storage device 01A, by obtaining a battery end cap assembly 100 with an area matching the pressure relief capacity, ensures smooth explosion-proof pressure relief and at the same time ensures the structural strength of the battery end cap assembly 100, thereby improving the safety of the energy storage device 01A.

In the present application, the energy storage device 01A may be the battery cell 1000 shown in FIGS. 11 and 12 , or the battery module 1000B shown in FIG. 13 , or the battery pack 1000C shown in FIG. 14 .

According to the battery cell 1000 of the embodiment of the present application, as shown in Figures 11-12, it includes: a shell 200, an electrode assembly 300 and a battery end cover assembly 100, the shell 200 has an opening 200a, the electrode assembly 300 is accommodated in the shell 200, the end cover 10 of the battery end cover assembly 100 covers the opening 200a, and the inner side surface 102 of the end cover 10 is arranged toward the electrode assembly 300.

12, the housing 200 is a component for accommodating the electrode assembly 300. The housing 200 may be a hollow structure with an opening 200a formed at one end, or a hollow structure with openings 200a formed at both ends. The housing 200 may be in various shapes, such as a cylinder, a cuboid, etc. The housing 200 may be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.

The number of electrode assemblies 300 in the housing 200 may be one or more. For example, as shown in FIG12 , there are more than one electrode assemblies 300 , and the plurality of electrode assemblies 300 are stacked.

The battery end cover assembly 100 is a component that covers the opening 200 a of the housing 200 to isolate the internal environment of the battery cell 1000 from the external environment.

Specifically, the battery end cap assembly 100 includes: an end cap 10, a terminal assembly 20 and a pressure relief mechanism 50, and the terminal assembly 20 and the pressure relief mechanism 50 are both arranged on the end cap 10. The graphic area formed by the outer contour of the end cap 10 is a first area S1, and the projection area of the pressure relief mechanism 50 on the end cap 10 is a second area S2, and the second area S2 accounts for 0.5%-5% of the first area S1.

According to the battery cell 1000 of the embodiment of the present application, the above-mentioned battery end cap assembly 100 is used, and the area occupied by the pressure relief mechanism 50 on the end cap 10 is reasonably set. After the pressure relief mechanism 50 is opened, there is a sufficiently large pressure relief port for exhaust, so that the end area size of the battery cell 1000 is more matched with the pressure relief capacity. In this way, the probability of untimely pressure relief is reduced, and the safety of the battery cell 1000 is improved. In addition, the overall structural strength of the battery end cap assembly 100 can be guaranteed, and it is not easy to deform after being under pressure, and the reliability of the entire battery cell 1000 can be enhanced.

It should be noted that in the present application, the battery cell 1000 may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery or a magnesium-ion battery, etc., and the embodiments of the present application do not limit this. The battery cell 1000 may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this. The battery cell 1000 is generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application do not limit this.

The housing 200 is provided with an electrode assembly 300 and an electrolyte. The electrode assembly 300 is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell 1000 mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. The positive electrode collector not coated with the positive electrode active material layer serves as a positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode collector may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide. The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode collector. The negative electrode collector not coated with the negative electrode active material layer protrudes from the negative electrode collector coated with the negative electrode active material layer. The negative electrode collector not coated with the negative electrode active material layer serves as a negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon, etc. In order to ensure that a large current can pass without melting, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the isolation film may be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly 300 may be a winding structure or a laminated structure, and the embodiments of the present application are not limited thereto.

Furthermore, the development of battery technology must take into account multiple design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters.

As shown in FIG3 , in a battery cell 1000, the battery end cap assembly 100 generally includes an end cap 10 and a terminal assembly 20. As shown in FIG10 , the terminal assembly 20 includes an electrode terminal 204 and a connector 205. The electrode terminal 204 is fixed to the end cap 10 via the connector 205. The electrode terminal 204 is used to be electrically connected to the electrode assembly 300. The electrode terminal 204 is a component for outputting electrical energy from the battery cell 1000.

In some embodiments, the ratio of the capacity a of the battery cell 1000 to the second area S2 is at least equal to 1.8, wherein the unit of the capacity a is ampere-hour (A·H), and the unit of the second area S2 is square millimeter (mm ^{^2} ). In this way, the capacity a of the battery cell 1000 and the area occupied by the pressure relief mechanism 50 can be further reasonably matched.

Therefore, the pressure relief port of the pressure relief mechanism 50 is relatively large. When the battery cell 1000 encounters abnormal conditions such as short circuit, overcharge, over discharge, etc., the internal pressure of the battery cell 1000 increases sharply. When the pressure reaches the set battery explosion-proof air pressure point, the pressure relief mechanism 50 can be opened instantly to ensure that the internal gas of the battery cell 1000 can be discharged in time to prevent the battery cell 1000 from exploding. It can play an instant and complete deflation to achieve the purpose of explosion-proof.

According to an embodiment of the present application, a battery module 1000B, as shown in FIG. 13 , includes a plurality of battery cells 1000 , and the plurality of battery cells 1000 are arranged in a certain sequence.

According to the battery pack 1000C of the embodiment of the present application, as shown in FIG14 , it includes a box 2000 and a battery module 1000B, wherein the box 2000 is used to accommodate at least one battery module 1000B. The battery module 1000B is composed of a plurality of battery cells 1000 arranged in a row, so the battery pack 1000C includes a box 2000 and a plurality of battery cells 1000.

Among them, the box body 2000 is a component for accommodating the battery cell 1000. The box body 2000 provides a storage space for the battery cell 1000. The box body 2000 can adopt a variety of structures. In some embodiments, the box body 2000 may include a first part and a second part, and the first part and the second part cover each other to define a storage space for accommodating the battery cell 1000. The first part and the second part may be in a variety of shapes, such as a cuboid, a cylinder, etc. The first part may be a hollow structure with one side open, and the second part may also be a hollow structure with one side open, and the open side of the second part covers the open side of the first part, thereby forming a box body 2000 with a storage space. It may also be that the first part is a hollow structure with one side open, and the second part is a plate-like structure, and the second part covers the open side of the first part, thereby forming a box body 2000 with a storage space. The first part and the second part can be sealed by a sealing element, and the sealing element may be a sealing ring, a sealant, etc. The box body 2000 can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cell 1000.

In the battery pack 1000C, there may be one or more battery cells 1000. If there are more than one battery cell 1000, the battery cells 1000 may be connected in series, in parallel or in a mixed connection. A mixed connection means that the battery cells 1000 are both connected in series and in parallel. The battery module 1000B may be formed by connecting the battery cells 1000 in series, in parallel or in a mixed connection, and the battery modules 1000B may be connected in series, in parallel or in a mixed connection to form a whole and accommodated in the box 2000. All the battery cells 1000 may also be directly connected in series, in parallel or in a mixed connection, and then the whole formed by all the battery cells 1000 may be accommodated in the box 2000.

In some embodiments, the battery pack 1000C may further include a busbar component, through which multiple battery cells 1000 may be electrically connected to each other, so as to realize series connection, parallel connection or mixed connection of multiple battery cells 1000. The busbar component may be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

According to the battery pack 1000C of the embodiment of the present application, the multiple battery cells 1000 therein all adopt the above-mentioned battery end cover assembly 100. During the assembly process of the battery pack 1000C, when one or several battery cells 1000 leak, they can be quickly identified, which can improve the maintenance convenience of the battery pack 1000C.

The technical solution described in the embodiment of the present application is applicable to the energy storage device 01A and the electrical equipment 01 using the energy storage device 01A.

The electrical equipment 01 may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy includes a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The present application embodiment does not impose any special restrictions on the above-mentioned electrical equipment 01.

For the convenience of description, the following embodiments are described by taking the electric device 01 as a vehicle as an example.

Please refer to FIG. 15 , which is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application. An energy storage device 01A is provided inside the vehicle, and the energy storage device 01A can be provided at the bottom, head, or tail of the vehicle. The energy storage device 01A can be used for power supply of the vehicle, for example, the energy storage device 01A can be used as an operating power source for the vehicle.

According to the electrical equipment 01 of the embodiment of the present application, the above-mentioned energy storage device 01A is used to improve the working stability, reliability and safety of the electrical equipment 01.

The vehicle may also include a controller and a motor, wherein the controller is used to control the energy storage device 01A to supply power to the motor, for example, to meet the power requirements for starting, navigating and driving the vehicle.

In some embodiments of the present application, the energy storage device 01A can not only be used as the operating power source of the vehicle, but also as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

The power-consuming device 01 may also be an energy storage device such as an energy storage cabinet, which can be used as a charging cabinet for mobile devices or as an energy storage device for other devices. For example, solar power generation equipment can be equipped with an energy storage cabinet, and the electricity generated by solar power generation is temporarily stored in the energy storage cabinet to power street lamps, bus stops and other devices.

In the description of this specification, the description with reference to the terms "embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

A battery end cap assembly, comprising:

End caps;

A terminal assembly, the terminal assembly being connected to the end cover;

A pressure relief mechanism, wherein the pressure relief mechanism is disposed on the end cover, and the pressure relief mechanism and the terminal assembly are spaced apart along the length direction of the end cover;

The graphic area formed by the outer contour of the end cover is the first area S1, the projection area of the pressure relief mechanism on the end cover is the second area S2, and the second area S2 accounts for 0.5%-5% of the first area S1;

The dimension of the pressure relief mechanism along the length direction of the end cover is b1, and the ratio of b1 to the length b0 of the end cover is 5% to 12%;

The dimension of the pressure relief mechanism along the width direction of the end cover is e1, and the ratio of e1 to the width e0 of the end cover is 15% to 25%.
The battery end cap assembly according to claim 1, wherein the pressure relief mechanism comprises an explosion-proof valve, and the explosion-proof valve comprises an opening area;

The explosion-proof valve is provided with a notched groove, and the notched groove is located in the opening area;

The minimum thickness of the explosion-proof valve at the notch groove is a first thickness n1, and the thickness of the explosion-proof valve at the opening area is a second thickness n2. The first thickness n1 is 15% to 25% of the second thickness n2.
The battery end cover assembly according to claim 2, wherein the projection area of the notch groove on the end cover is a third area S3, and the third area S3 accounts for 1.0% to 1.5% of the second area S2.
The battery end cover assembly according to claim 2 or 3, wherein the explosion-proof valve has a tensile strength of 90 to 130 N/mm ^2 .
The battery end cover assembly according to any one of claims 2 to 4, wherein the contour line of the notch groove on a cross section perpendicular to the extension direction of the notch groove is U-shaped or C-shaped.
The battery end cover assembly according to any one of claims 2 to 5, wherein the contour line of the notch groove on the cross section perpendicular to the extension direction of the notch groove comprises an arc line, and the radius r1 of the arc line is 0.05-0.15 mm.
The battery end cover assembly according to any one of claims 2-6, wherein the minimum spacing between the pressure relief mechanism and the terminal assembly is b2, and b2>b1.
The battery end cap assembly according to claim 7, wherein 25%≤b1/b2≤35%.
The battery end cover assembly according to any one of claims 1 to 8, wherein the pressure relief mechanism is located at the geometric center of the figure formed by the outer contour of the end cover.
The battery end cover assembly according to any one of claims 1 to 9, wherein the end cover is provided with a liquid injection hole penetrating along the thickness direction thereof, and the liquid injection hole is located between the terminal assembly and the pressure relief mechanism;

The minimum distance between the injection hole and the pressure relief mechanism is b3, and the minimum distance between the injection hole and the terminal assembly is b4, 1.5≤b3/b4≤2.
According to any one of claims 1-10, the battery end cover assembly is two and is respectively a positive terminal assembly and a negative terminal assembly, the pressure relief mechanism is located between the two terminal assemblies, the axial distance between the two terminal assemblies is D1, the minimum distance between the axis of the negative terminal assembly and the outer contour of the end cover is D2, 5≤D1/D2≤7.
An energy storage device, comprising: a battery end cover assembly according to any one of claims 1-11.
An electrical equipment, comprising the energy storage device according to claim 12.