Patent Description:
In the related art, each of a mobile phone, a notebook computer, an electric tool, an electric vehicle, etc. adopts batteries as a power source, for example, the electric vehicle needs to adopt a power battery pack composed of a plurality of batteries.

A battery is provided with an anti-explosion and pressure relief structure on a cover plate, for example, the cover plate of the battery is provided with a thin-walled valve body, when an internal pressure of the battery exceeds a specified value, a thin wall of the valve body ruptures to release the internal pressure, and thus, the battery is prevented from being exploded and fractured. In an existing solution, the anti-explosion and pressure relief structure is relatively constant in specification and has the situation of untimely pressure relief caused by overhigh relief pressure, and thus, the safety of the battery is affected. <CIT> describes a secondary battery which comprises a shell, a first cover plate and a second cover plate, the shell is of a cylindrical structure, a first opening and a second opening which are opposite to each other are formed in the extending direction of the shell, the first cover plate covers the first opening, the second cover plate covers the second opening, a first explosion-proof valve is arranged on the first cover plate, and a second explosion-proof valve is arranged on the second cover plate. <CIT> discloses a rectangular battery cell including an end cover assembly having an end cover, electrode terminals and a pressure relief valve mechanism mounted on a hole of the end cover. <CIT> discloses a rectangular battery cell including an electrode assembly enclosed in a case and covered by a lid.

The purpose of the present application is to at least solve one of technical problems existing in the prior art. Therefore, the present application provides a battery end cover assembly by which the area taken up by a pressure relief mechanism is more matched with the area of an end cover, and thus, the battery end cover assembly is matched with the pressure relief capacity of a battery.

The present application further provides an energy storage apparatus adopting the above-mentioned battery end cover assembly.

The present application further provides an electric device adopting the above-mentioned energy storage apparatus.

The battery end cover assembly according to an embodiment in a first aspect of the present application includes an end cover of a rectangle; terminal assemblies, the terminal assemblies being connected to the end cover; and a pressure relief mechanism, the pressure relief mechanism being disposed on the end cover, and the pressure relief mechanism and the terminal assemblies being distributed at intervals in the length direction of the end cover; wherein the area of a figure formed by an outer contour of the end cover is a first area S1, the area of a projection of the pressure relief mechanism on the end cover is a second area S2, and the second area S2 accounts for <NUM>% to <NUM>% of the first area S1. The size of the pressure relief mechanism in the length direction of the end cover is b1, and b1 accounts for <NUM>% to <NUM>% of the length b0 of the end cover; and the size of the pressure relief mechanism in the width direction of the end cover is e1, and e1 accounts for <NUM>% to <NUM>% of the width e0 of the end cover. An area of the preset opening area is at least a half of the second area S2 and not more than <NUM>% of the second area S2. A ratio of a capacity a of the energy storage apparatus to the second area is at least equal to <NUM>, wherein the unit of the capacity a is ampere-hour (AH), and the unit of the second area S2 is mm<NUM>.

The energy storage apparatus according to an embodiment in a second aspect of the present application includes the battery end cover assembly according to the above-mentioned embodiment.

The electric device according an embodiment in a third aspect of the present application includes the energy storage apparatus according to the above-mentioned embodiment.

Reference numerals in the accompanying drawings:.

A battery end cover assembly <NUM> according to an embodiment of the present application will be described below with reference to the accompanying drawings.

With reference to <FIG>, a battery end cover assembly <NUM> according to an embodiment in a first aspect of the present application includes an end cover <NUM>, terminal assemblies <NUM> and a pressure relief mechanism <NUM>, and the terminal assemblies <NUM> and the pressure relief mechanism <NUM> are both disposed on the end cover <NUM>. The end cover <NUM> is an end sealing cover of a battery, and the terminal assemblies <NUM> are used for internal and external electric energy transmission of the battery.

The pressure relief mechanism <NUM> is a component for relieving an internal pressure of the battery. The pressure relief mechanism <NUM> is disposed on the end cover <NUM>, and when the internal pressure or temperature of the battery reaches a threshold value, the internal pressure of the battery is relieved by the pressure relief mechanism <NUM>. The pressure relief mechanism <NUM> may be a component such as an anti-explosion valve <NUM>, an anti-explosion sheet, a pressure relief valve and a one-way valve.

In some embodiments, the end cover <NUM> is provided with terminal leading-out holes <NUM> penetrating in the thickness direction thereof, and the terminal assemblies <NUM> are connected to the end cover <NUM> and cover the terminal leading-out holes <NUM>. The terminal assemblies <NUM> cover the terminal leading-out holes <NUM> to play a role in sealing the terminal leading-out holes <NUM>. Of course, in other embodiments of the present application, it is also possible that the end cover <NUM> is not provided with the terminal leading-out holes <NUM>, and the terminal assemblies <NUM> are integrally formed on the end cover <NUM>.

The pressure relief mechanism <NUM> is located on a geometric center of a figure formed by an outer contour of the end cover <NUM>. For example, in <FIG>, the end cover <NUM> is of a rectangle, and the pressure relief mechanism <NUM> is located on the intersection point of diagonal lines of the rectangle. Here, the distance from the pressure relief mechanism <NUM> to each position of the edge of the end cover <NUM> is relatively balanced, and an exhaust path from the inside of the battery to the pressure relief mechanism <NUM> is relatively short as a whole, which is beneficial to the improvement of a pressure relief effect, so that the situation of untimely pressure relief caused by an overlong distance between a partial position inside the battery and the pressure relief mechanism <NUM> is avoided, and the probability of partial explosion caused by untimely pressure relief is reduced. In other embodiments of the present application, it is also possible that the pressure relief mechanism <NUM> is not disposed in the center of the end cover <NUM>, at the moment, the distance between the pressure relief mechanism <NUM> and the edge of the end cover <NUM> is also required to be reasonably set.

The area of the figure formed by the outer contour of the end cover <NUM> is a first area S1, the area of a projection of the pressure relief mechanism <NUM> on the end cover <NUM> is a second area S2, and the second area S2 accounts for <NUM>% to <NUM>% of the first area S1. With a solution as shown in <FIG> as an example, the end cover <NUM> is of a rectangle, the length of the end cover <NUM> is b0, the width of the end cover <NUM> is e0, and the first area S1 of the outer contour of the end cover <NUM> is expressed as S1=b0×e0. The projection of the pressure relief mechanism <NUM> on the end cover <NUM> is of a runway shape including a rectangle in the middle and semicircles on two ends and having the length b1 and the width e1, and the second area S2 of the runway shape is expressed as S2=(b1-e1)×e1+π×(e1÷<NUM>)<NUM>. At the moment, the second area S2 is controlled to be <NUM>% to <NUM>% of the first area S1.

It can be understood that the pressure relief mechanism <NUM> is a weak area on the battery end cover assembly <NUM>, the pressure relief mechanism <NUM> is provided with a thin wall (or a structure such as a notch or a flexible membrane), when the internal pressure of temperature of the battery reaches the threshold value, the thin wall (or the structure such as the notch or the flexible membrane) is opened or torn off to release the internal pressure, and thus, the battery is prevented from being exploded or fractured. Therefore, the area of the pressure relief mechanism <NUM> on the end cover <NUM> not only can determine the pressure relief capacity, but also can affect the overall structural strength of the battery end cover assembly <NUM>.

In the present application, by limiting the proportion of the second area S2 to the first area S1 to be not less than <NUM>%, the area taken up by the pressure relief mechanism <NUM> cannot be too small, there is a pressure relief opening large enough for exhaust after the pressure relief mechanism <NUM> is opened, so that the size of the battery end cover assembly <NUM> is relatively matched with the pressure relief capacity. In this way, the probability of untimely pressure relief is reduced, and the safety of a battery is improved.

In the present application, by limiting the proportion of the second area S2 to the first area S1 to be not more than <NUM>%, the area taken up by the pressure relief mechanism <NUM> cannot be too large, in this way, the overall structural strength of the battery end cover assembly <NUM> can be guaranteed, and the battery end cover assembly is not easy to deform after bearing a pressure. Moreover, after the area taken up by the pressure relief mechanism <NUM> is reduced, the edge, on the pressure relief mechanism <NUM>, of the end cover <NUM> is also not easy to deform, so that the probability that the pressure relief mechanism <NUM> falls off to be invalid is reduced, and the reliability of the overall battery can be improved.

Optionally, the proportion of the second area S2 to the first area S1 may be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% and <NUM>%.

With reference to <FIG>, a battery end cover assembly <NUM> of the present application includes an end cover <NUM>, terminal assemblies <NUM> and a pressure relief mechanism <NUM>, and the terminal assemblies <NUM> and the pressure relief mechanism <NUM> are both disposed on the end cover <NUM>. The pressure relief mechanism <NUM> and the terminal assemblies <NUM> are distributed at intervals in the length direction of the end cover <NUM>. The size of the pressure relief mechanism <NUM> in the length direction of the end cover <NUM> is b1 which is referred to as the length of the pressure relief mechanism <NUM>, and the length b1 of the pressure relief mechanism <NUM> accounts for <NUM>% to <NUM>% of the length b0 of the end cover <NUM>. The size of the pressure relief mechanism <NUM> in the width direction of the end cover <NUM> is e1 which is referred to as the width of the pressure relief mechanism <NUM>, and the width e1 of the pressure relief mechanism <NUM> accounts for <NUM>% to <NUM>% of the width e0 of the end cover <NUM>.

It can be understood that the pressure relief mechanism <NUM> is a weak area on the battery end cover assembly <NUM>, the pressure relief mechanism <NUM> may be extruded when the internal pressure of the battery is overhigh, and thus, the battery end cover assembly <NUM> deforms to a certain extent.

The pressure relief mechanism <NUM> is spaced from the terminal assemblies <NUM> in the length direction of the end cover <NUM>. On one hand, the terminal assemblies <NUM> can keep away from the pressure relief mechanism <NUM>, the centralized stresses on the terminal assemblies <NUM> are relatively small when the internal pressure of the battery is relatively high, and thus, loss, connection falling off, etc. caused by overhigh pressure borne by the terminal assemblies <NUM> are avoided. On the other hand, the length size of the end cover <NUM> can be utilized, and the pressure relief mechanism <NUM> may be spaced from the terminal assemblies <NUM> for a certain distance, so that mutual interference and influences to each other are avoided.

By controlling the proportion of the length b1 of the pressure relief mechanism <NUM> to the length b0 of the end cover <NUM> to be at least <NUM>%, and controlling the proportion of the width e1 of the pressure relief mechanism <NUM> to the width e0 of the end cover <NUM> to be at least <NUM>%, the pressure relief mechanism <NUM> can take up an area large enough for pressure relief and exhaust, thereby guaranteeing the smoothness of exhaust.

By controlling the proportion of the length b1 of the pressure relief mechanism <NUM> to the length b0 of the end cover <NUM> to be not more than <NUM>%, a distance which is long enough can be reserved between two sides, located on the pressure relief mechanism <NUM>, of the end cover <NUM> to place structures such as the terminal assemblies <NUM>. By controlling the proportion of the width e1 of the pressure relief mechanism <NUM> to the width e0 of the end cover <NUM> to be not more than <NUM>%, the probability that the side, located on the pressure relief mechanism <NUM>, of the end cover <NUM> is too narrow to be easily fractured is reduced. By controlling the length and width of the pressure relief mechanism <NUM>, the structural strength of the end cover <NUM> can be guaranteed while the pressure relief capacity can be guaranteed, and the situation that the end cover <NUM> is bent and fractured when bearing an impact and a pressure is avoided.

After the length b1 of the pressure relief mechanism <NUM> is limited, a certain space may be vacated on the end cover <NUM> to place the terminal assemblies <NUM>, so that mounting inconvenience and even mutual interference caused by disposing the pressure relief mechanism <NUM> to be too close to the terminal assemblies <NUM> are avoided. Furthermore, the length b1 of the pressure relief mechanism <NUM> is limited to avoid excessive deformation caused by an overlarge bending moment borne due to the overlarge length of the pressure relief mechanism <NUM>, so that the situation that the pressure relief mechanism <NUM> is easy to fall off due to the excessive deformation is avoided, in this way, the problems that the exhaust direction cannot be limited and the exhaust is obstructed by the separated pressure relief mechanism <NUM> due to the fact that the pressure relief mechanism <NUM> is ejected away from the end cover <NUM> by a high-pressure gas at high pressure are also avoided.

The proportion of the area of the pressure relief mechanism <NUM> to the area of the end cover <NUM> (i.e. the proportion of the second area S2 to the first area S1) is <NUM>% to <NUM>%, the proportion of the length of the pressure relief mechanism <NUM> to the length of the end cover <NUM> (i.e. the proportion of the length b1 to the length b0) is <NUM>% to <NUM>%, and the proportion of the width of the pressure relief mechanism <NUM> to the width of the end cover <NUM> (i.e. the proportion of the width e1 to the width e0) is <NUM>% to <NUM>%, so that the pressure relief mechanism <NUM> can take up an area large enough for pressure relief and exhaust, thereby guaranteeing smooth and timely exhaust. Meanwhile, each side, located on the pressure relief mechanism <NUM>, of the end cover <NUM> does not have to be set to be too narrow, so that the risk that the edge of the end cover <NUM> is easily fractured due to the overlarge length and width of the pressure relief mechanism <NUM> is avoided, and the situation that the end cover <NUM> is bent and fractured when bearing an impact and a pressure is avoided. Moreover, there is a sufficient space for arranging components on the end cover <NUM> so that all the components can be spaced without mutual interference. Furthermore, the structural strength of the end cover <NUM> can be guaranteed, excessive deformation caused when the end cover <NUM> bears a pressure is avoided, the probability that a gas is exhausted from the edge of the end cover <NUM> when the internal temperature or pressure of the battery is overhigh is avoided, it is ensured that the gas is only exhausted from the pressure relief mechanism <NUM>, the exhaust direction of the gas in the battery can be effectively controlled, it is convenient to perform subsequent treatment on exhausted electrolyte or high-temperature gas, and unwanted corrosion, fire hazards, etc. caused by arbitrary emission of the electrolyte or high-temperature gas in the battery are avoided.

Optionally, the proportion of the length b1 of the pressure relief mechanism <NUM> to the length b0 of the end cover <NUM> is <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, etc..

Optionally, the proportion of the width e1 of the pressure relief mechanism <NUM> to the width e0 of the end cover <NUM> is <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, etc..

A battery end cover assembly <NUM> according to the present application includes an end cover <NUM>, terminal assemblies <NUM> and a pressure relief mechanism <NUM>, and the terminal assemblies <NUM> and the pressure relief mechanism <NUM> are both disposed on the end cover <NUM>. As shown in <FIG>, the size of the pressure relief mechanism <NUM> in the length direction of the end cover <NUM> is b1, the minimum distance between the pressure relief mechanism <NUM> and each of the terminal assemblies <NUM> is b2, and b2>b1. By such disposing, the terminal assemblies <NUM> and other external components connected to the terminal assemblies <NUM> can be spaced from the pressure relief mechanism <NUM> by a sufficient distance. After the pressure relief mechanism <NUM> is opened, the pressure relief mechanism <NUM> is not easily blocked by the other external components, the probability that the internal gas and the electrolyte are ejected on the terminal assemblies <NUM> and the other external components when the pressure relief mechanism <NUM> performs pressure relief can be reduced, and the probability that the other external components catch fire is reduced. Moreover, after the pressure relief mechanism <NUM> is spaced from the terminal assemblies <NUM> for a safe distance, the risk of short circuit caused by conducting the positive and negative electrodes of the battery by an ejected material from the pressure relief mechanism <NUM> is not easily caused, and therefore, the safety of the battery can be improved.

Optionally, the minimum distance between the pressure relief mechanism <NUM> and each of the terminal assemblies <NUM> is b2, the length of the pressure relief mechanism <NUM> is b1, and <NUM>%≤b1/b2≤<NUM>%. By such disposing, the distance between the pressure relief mechanism <NUM> and each of the terminal assemblies <NUM> can be long enough, and therefore, the risk that the ejected material from the pressure relief mechanism <NUM> is ejected to the terminal assemblies <NUM> is further reduced. Moreover, the pressure relief mechanism <NUM> and the terminal assemblies <NUM> are reasonably distributed on the end cover <NUM>, so that interference generated by disposing the terminal assemblies <NUM> to be too close to the edge of the end cover <NUM> is avoided.

The terminal assemblies <NUM> are closer to the edge of the end cover <NUM> with respect to the pressure relief mechanism <NUM>. As the edge of the end cover <NUM> is supported, the structural strength on the positions of the terminal assemblies <NUM> can be improved by virtue of the support borne by the edge of the end cover <NUM>, pressures borne on the terminal assemblies <NUM> when the battery end cover assembly <NUM> bears a pressure can be reduced, and the probability that the terminal assemblies <NUM> are damaged to fall off can be reduced.

Further, optionally, b1/b2 may be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, etc..

With reference to <FIG>, a battery end cover assembly <NUM> the present application includes an end cover <NUM>, terminal assemblies <NUM> and a pressure relief mechanism <NUM>, and the terminal assemblies <NUM> and the pressure relief mechanism <NUM> are both disposed on the end cover <NUM>. As shown in <FIG> and <FIG>, the pressure relief mechanism <NUM> includes an anti-explosion valve <NUM>, and the anti-explosion valve <NUM> includes a preset opening area <NUM>. For facilitating description, here, the outer edge of the preset opening area <NUM> is referred to as a predetermined open boundary <NUM>.

The preset opening area <NUM> is an area reserved for pressure relief when the anti-explosion valve <NUM> is designed. If pressure relief is required when the internal temperature or pressure of the battery is increased, the preset opening area <NUM> is opened, so that a pressure relief opening is formed in the anti-explosion valve <NUM>, and the gas in the battery is exhausted from the pressure relief opening formed after the preset opening area <NUM> is opened. The predetermined open boundary <NUM> is an edge contour of the pressure relief opening formed after the preset opening area <NUM> is opened.

Specifically, the area of the preset opening area <NUM> accounts for at least a half of the area of the anti-explosion valve <NUM> (i.e. the second area S2), and after the preset opening area <NUM> is opened, the pressure relief opening large enough is obtained for exhaust. The area of the preset opening area <NUM> is reasonably set, and thus, the pressure relief capacity of the anti-explosion valve <NUM> can be guaranteed.

Further, the proportion of the area of the preset opening area <NUM> to the area of the anti-explosion valve <NUM> is not more than <NUM>%, and an edge large enough is reserved for fixing or connecting the anti-explosion valve <NUM>, so that the anti-explosion valve <NUM> is not easy to fall off, and the working reliability of the anti-explosion valve <NUM> is improved.

The anti-explosion valve <NUM> is adopted for pressure relief, compared with a component such as a pressure relief valve and a one-way valve, the anti-explosion valve <NUM> is relatively thin, it is unnecessary to vacate overmuch space for the pressure relief mechanism <NUM>, which is beneficial to the improvement of the arrangement intensity of an internal structure of the battery, thereby being beneficial to the increment of the energy density of the battery. Moreover, after the internal structure of the battery is tightly arranged, the structural strength is also favorably improved. Moreover, in parts of embodiments, an inner side surface <NUM> (the surface, facing to the inside of the battery, of the end cover <NUM>) of the end cover <NUM> is connected with an insulation board <NUM> which does not need to vacate overmuch space in correspondence to the anti-explosion valve <NUM>, in this way, the insulation board <NUM> can provide a greater supporting effect for the end cover <NUM> to reduce the deformation level after the battery end cover assembly <NUM> bears a pressure.

The tensile strength of the anti-explosion valve <NUM> is <NUM>-<NUM> N/mm<NUM>, in this way, the situation that the anti-explosion valve <NUM> is opened when the internal pressure or temperature does not reach a threshold value due to instable performance caused by overlow tensile strength is avoided, and the situation that untimely exhaust caused by difficulty in opening the anti-explosion valve <NUM> due to overhigh tensile strength is also avoided. Therefore, the reasonable setting of the tensile strength of the anti-explosion valve <NUM> is beneficial to the improvement of the performance playing reliability and stability.

Specifically, within the range of the tensile strength <NUM>-<NUM> N/mm<NUM> of the anti-explosion valve <NUM>, the tolerance pressure which can be borne by the anti-explosion valve <NUM> is approximately <NUM>-<NUM> MPa. Therefore, the tensile strength of the anti-explosion valve <NUM> should not be lower than <NUM> N/mm<NUM>, the tolerance pressure which can be borne by the anti-explosion valve <NUM> is prevented from being far lower than <NUM> MPa, and the situation that the anti-explosion valve <NUM> is opened due to partial temporary temperature or pressure rise inside the battery is avoided, so that the anti-explosion valve <NUM> cannot be damaged under reasonable temperature or pressure variation, and the error rate of the anti-explosion valve <NUM> is reduced. The tensile strength of the anti-explosion valve <NUM> should not be more than <NUM> N/mm<NUM>, and the tolerance pressure which can be borne by the anti-explosion valve <NUM> is prevented from being far more than <NUM> MPa, so that the situation that the anti-explosion valve <NUM> is still not opened when there is an explosion risk inside the battery is avoided, and it is ensured that the anti-explosion valve <NUM> can be opened in time for exhaust. An appropriate tensile strength is selected for the anti-explosion valve <NUM>, so that the anti-explosion valve <NUM> is not easily damaged during machining and assembling, and the production defect rate of the battery end cover assembly is reduced.

Optionally, the tensile strength of the anti-explosion valve <NUM> is <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, etc. (unit: N/mm<NUM>). Further, optionally, the tensile strength of the anti-explosion valve <NUM> is <NUM> N/mm<NUM>.

As shown in <FIG>, the anti-explosion valve <NUM> is provided with a notch groove <NUM>, and the anti-explosion valve <NUM> on the position of the notch groove <NUM> is the thinnest, which is beneficial to the timely pressure relief and exhaust. Of course, solutions of the present application are not limited thereto, the preset opening area <NUM> can also be set to be of a thin wall as a whole, and any part of the thin wall can be torn off when being impacted by a pressure.

In a solution of the present application, there are one or more notch grooves <NUM> in the anti-explosion valve <NUM>. When there are a plurality of notch grooves <NUM> in the anti-explosion valve <NUM>, the plurality of notch grooves <NUM> can be at least partially connected, or the plurality of notch grooves <NUM> can be disposed at intervals, which is not limited herein. In an example as shown in <FIG>, the anti-explosion valve <NUM> is provided with a C-shaped notch groove <NUM>. In an example as shown in <FIG>, the anti-explosion valve <NUM> is provided with two C-shaped notch grooves <NUM> disposed at intervals. The shape of each notch groove <NUM> may also be referred to as a runway shape, and such an anti-explosion valve <NUM> in <FIG> may also be referred to as a double-runway-shaped anti-explosion valve. In some further examples, the anti-explosion valve <NUM> is provided with two C-shaped notch grooves <NUM> disposed symmetrically, and such an anti-explosion valve <NUM> may also be referred to as a double-C-shaped anti-explosion valve.

As shown in <FIG> and <FIG>, the minimum thickness of the anti-explosion valve <NUM> on the position of the notch groove <NUM> is a first thickness n1, the thickness of the anti-explosion valve on the position of the preset opening area <NUM> is n2, and n1 accounts for <NUM>% to <NUM>% of n2. Here, the thickness proportions of the anti-explosion valve <NUM> on the positions of the notch groove <NUM> and the preset opening area <NUM> are limited, so that the preset opening area <NUM> cannot to be too thick while the anti-explosion valve <NUM> on the position of the notch groove <NUM> is relatively thin. The anti-explosion valve <NUM> on the position of the notch groove <NUM> is relatively thin, so that the anti-explosion valve <NUM> on the position of the notch groove <NUM> can be opened in time when an internal pressure or temperature of the battery reaches a threshold value. The preset opening area <NUM> cannot be too thick, so that the preset opening area <NUM> is easily impacted by the high-pressure gas after the position of the notch groove <NUM> is opened, and the pressure relief opening can be completely opened for smooth exhaust. By limiting the thickness of the anti-explosion valve <NUM> on the position of the preset opening area <NUM> to be at least four times as large as the thickness of that on the position of the notch groove <NUM>, when the anti-explosion valve <NUM> is impacted by the internal pressure or is overhigh in temperature, the pressure can be centralized on the position of the notch groove <NUM>, and the position, where the pressure is centralized on the position of the notch groove <NUM>, of the anti-explosion valve <NUM> is opened, so that more timely exhaust is achieved, and the working sensitivity of the anti-explosion valve <NUM> is favorably improved.

Optionally, the ratio of n1 to n2 may be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, etc..

As shown in <FIG> and <FIG>, the area of a projection of the notch groove <NUM> on the end cover <NUM> is a third area S3, and the third area S3 accounts for <NUM>% to <NUM>% of the second area S2. The second area S2 is the area of a projection of the anti-explosion valve <NUM> on the end cover <NUM>.

In a solution as shown in <FIG>, the projection of the anti-explosion valve <NUM> on the end cover <NUM> is of a runway shape, and the area taken up by the runway shape is the second area S2. A projection of the notch groove <NUM> on the end cover <NUM> is of a C-shaped strip in a dash area in <FIG>, and the area of this dash area is the third area S3. Moreover, in a solution as shown in <FIG>, the projection of the anti-explosion valve <NUM> on the end cover <NUM> is of a runway shape, and the area taken up by the runway shape is the second area S2. There are two notch grooves <NUM>, projections on the end cover <NUM> are of two C-shaped strips shown as dash areas in <FIG>, areas of the two C-shaped strips are respectively S31 and S32, and the area of the dash area is expressed as S3=S31+S32.

Here, the third area S3 is limited to account for <NUM>% to <NUM>% of the second area S2, that is, the area taken up on the anti-explosion valve <NUM> by the thinnest area on the anti-explosion valve <NUM> is limited. The proportion of the third area S3 to the second area S2 cannot be too small, there may be more areas on the position of the notch groove <NUM> to induce pressure or temperature variation when the internal pressure or temperature of the battery reaches the threshold value, so that the anti-explosion valve can be opened in time for pressure relief, and then, the working sensitivity of the anti-explosion valve <NUM> can be improved.

The limitation for the proportion of the third area S3 to the second area S2 does not affect the timely opening of the anti-explosion valve <NUM> when the internal pressure or temperature of the battery varies, however, the third area S3 is relatively small, which can effectively prevent an external impact force from acting on the notch groove <NUM> and prevent the anti-explosion valve <NUM> from being opened when the battery end cover assembly <NUM> is bumped by accident, and therefore, the working stability of the anti-explosion valve <NUM> can be improved.

When the pressure relief mechanism <NUM> is located on a geometric center of a figure formed by the outer contour of the end cover <NUM> and the internal pressure or temperature of the battery is overhigh, the end cover <NUM> may deform, the geometric center of the end cover <NUM> is away from the edge of the end cover <NUM> to generate relatively high deformation, so that the anti-explosion valve <NUM> can induce deformation variation caused by the variation of the internal pressure in time, and the notch groove <NUM> in the anti-explosion valve <NUM> can be rapidly opened for exhaust in time.

Optionally, the proportion of the third area S3 to the second area S2 may be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, etc..

The notch groove <NUM> is located in the preset opening area <NUM>. In some optional embodiments, the notch groove <NUM> is located in a predetermined open boundary <NUM>, that is, the notch groove <NUM> is disposed along the predetermined open boundary <NUM>. For example, when the predetermined open boundary <NUM> is a rectangular line, a rectangular area defined by the predetermined open boundary <NUM> is the preset opening area <NUM>, and the notch groove <NUM> is disposed along the rectangular line. When bearing a pressure, the anti-explosion valve <NUM> on the position of the notch groove <NUM> is fractured, and thus, a rectangular pressure relief opening can be formed. At the moment, the torn-off preset opening area <NUM> can be completely separated from the remaining parts of the anti-explosion valve <NUM> and can also be connected, on one side, to the remaining parts.

In some other optional embodiments, the notch groove <NUM> does not have to be disposed along the predetermined open boundary <NUM>. For example, when the predetermined open boundary <NUM> is the rectangular line, the rectangular area defined by the predetermined open boundary <NUM> is the preset opening area <NUM>, and the notch groove <NUM> is disposed along diagonal lines of the preset opening area <NUM>. When bearing a pressure, the anti-explosion valve <NUM> on the position of the notch groove <NUM> is fractured, the preset opening area <NUM> can be torn off along the diagonal lines to form four triangular areas. After the preset opening area <NUM> is opened, the formed pressure relief opening is rectangular.

Optionally, segments of the notch groove <NUM> can be partially disposed along the predetermined open boundary <NUM> and partially located in the preset opening area <NUM>. Therefore, the shape of the notch groove <NUM> is flexibly set.

With a solution as shown in <FIG> as an example, the notch groove <NUM> includes two first notch segments <NUM> oppositely disposed and arc-shaped, a linear second notch segment <NUM> and two third notch segments <NUM> disposed at intervals and linear, wherein the second notch segment <NUM> is disposed in parallel to the third notch segments <NUM>, two ends of the second notch segment <NUM> are respectively connected to the two first notch segments <NUM>, and each of the third notch segments <NUM> is connected to the corresponding first notch segment <NUM>. The first notch segments <NUM>, the second notch segment <NUM> and the third notch segments <NUM> are located on the predetermined open boundary <NUM>, and the part, located between the two third notch segments <NUM>, of the predetermined open boundary <NUM> is a connecting line <NUM>.

In other words, the second notch segment <NUM> is connected to one end of each of the two first notch segments <NUM>, the other end of each of the two first notch segments <NUM> is connected to one of the third notch segments <NUM>, and the two third notch segments <NUM> are disposed at intervals. The part located between the two third notch segments <NUM> is the connecting line <NUM>, and the outer edges of orthographic projections of the connecting line <NUM> and the notch groove <NUM> jointly form the predetermined open boundary <NUM>.

After such disposing, when being opened, the preset opening area <NUM> can be kept connected on the part on the connecting line <NUM>, so that the situation that the preset opening area <NUM> is completely separated from the remaining parts after being opened is avoided. Particularly, when pressure relief is needed, the preset opening area <NUM> may be adhered with electrolyte, etc. and even catches fire in case that an accident occurs; and by connecting the preset opening area <NUM> to the end cover <NUM>, the burning preset opening area <NUM> is prevented from being ejected out, and the probability that the fire spreads outwards is reduced.

As shown in <FIG>, the anti-explosion valve <NUM> is provided with a notch groove <NUM>. As shown in <FIG> and <FIG>, the minimum thickness of the anti-explosion valve <NUM> on the position of the notch groove <NUM> is a first thickness n1 which is <NUM>-<NUM>. By such disposing, the sensitivity of the anti-explosion valve <NUM> can be further improved, and the safety is improved. After the range of the first thickness n1 is limited here, the anti-explosion valve <NUM> can be limited to have an appropriate tolerance pressure value and can be opened for exhaust in time when the internal temperature or pressure of the battery is overhigh. The range of a radius r1 of a circular arc line is limited, which is beneficial to the uniform distribution of internal stresses of the anti-explosion valve <NUM> on the wall surface of the notch groove <NUM> along the circular arc line, and greatly reduces a difference of the internal stresses on all positions of the circular arc line. In this way, when the internal pressure or temperature of the battery varies to make the anti-explosion valve <NUM> deform, the anti-explosion valve <NUM> is opened in the notch groove <NUM> due to deformation. At the moment, the fracture of the anti-explosion valve <NUM> in the notch groove <NUM> is mainly caused by bearing the variation of the internal temperature and pressure, the influences from the centralized internal stresses are reduced, and thus, an actual tolerance pressure value of the anti-explosion valve <NUM> is more accurate.

Specifically, the tensile strength of the anti-explosion valve <NUM> is <NUM>-<NUM> N/mm<NUM>, and the first thickness n1 of which is <NUM>-<NUM>, so that the exhaust pressure of the anti-explosion valve <NUM> to the battery can reach an appropriate threshold value.

As shown in <FIG>, the anti-explosion valve <NUM> is provided with a notch groove <NUM>. As shown in <FIG> and <FIG>, a contour line on a section of the notch groove (<NUM>), perpendicular to the extension direction of the notch groove (<NUM>), is U-shaped or C-shaped. Of course, some solutions in which the contour line on the section, perpendicular to the extension direction of the notch groove <NUM>, of the notch groove <NUM> is rectangular or triangular or polygonal are not excluded in solutions of the present application. However, comparatively, by adopting the U-shaped or C-shaped section, sharp corners on the contour of the notch groove <NUM> are reduced, the situation that the anti-explosion valve <NUM> generates overhigh centralized stresses on the weakest position is avoided, and thus, the probability that the anti-explosion valve <NUM> is opened on the position of a sharp corner due to overhigh centralized internal stresses is avoided. Therefore, by such disposing, the working reliability of the anti-explosion valve <NUM> can be improved.

For the production of the anti-explosion valve <NUM>, the notch groove <NUM> is generally formed in a cutting or stamping way. As the contour line on the section, perpendicular to the extension direction of the notch groove <NUM>, of the notch groove <NUM> is U-shaped or C-shaped, the design of the sharp corner is avoided, the situation that too many burrs are generated by the sharp corner during machining is avoided, the probability that the sharp corner is torn off by pulling and dragging the burrs during production is avoided, and thus, a tolerance pressure value of the anti-explosion valve <NUM> is prevented from being reduced.

Specifically, the contour line on a section of the notch groove (<NUM>), perpendicular to the extension direction of the notch groove (<NUM>), includes a circular arc line of which the radius r1 is <NUM>-<NUM>. Here, the radius r1 of the circular arc line is limited to be at least <NUM>, therefore, on one hand, it is easy to machine the circular arc contour, and on the other hand, centralized stresses generated here are effectively reduced. The radius r1 of the circular arc line is limited to be not greater than <NUM>, so that the depth of the notch groove <NUM> and the minimum thickness of the anti-explosion valve <NUM> on the position of the notch groove <NUM> can be reasonably distributed.

Optionally, the radius r1 of the circular arc line may be <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, etc..

Specifically, the minimum thickness of the anti-explosion valve <NUM> on the position of the notch groove <NUM> is a first thickness n1 which is <NUM>-<NUM>. The contour line on the section, perpendicular to the extension direction of the notch groove <NUM>, of the notch groove <NUM> includes the circular arc line of which the radius r1 is <NUM>-<NUM>, which is beneficial to the implementation that the exhaust pressure of the anti-explosion valve <NUM> reaches an exhaust pressure or temperature threshold value required by the battery.

In a solution of the present application, the anti-explosion valve <NUM> is relatively flexible in disposing way, for example, the anti-explosion valve <NUM> can be integrally formed on the end cover <NUM>. For example, the notch groove <NUM> is stamped in the end cover <NUM> to facilitate pressure relief of the end cover <NUM> here, and thus, the anti-explosion valve <NUM> is formed. In such a way, during machining, the battery end cover assembly <NUM> has a small number of parts, so that the production efficiency is higher.

For another example, as shown in <FIG>, the end cover <NUM> is provided with a mounting hole <NUM>, and the anti-explosion valve <NUM> is connected to the end cover <NUM> and covers the mounting hole <NUM>. Comparatively, such a structure has the advantage that the size of the anti-explosion valve <NUM> is relatively flexibly selected, an anti-explosion valve <NUM> with an appropriate thickness can be selected as required, thereby obtaining more suitable pressure relief capacity.

In some embodiments, as shown in <FIG>, the battery end cover assembly <NUM> further includes an anti-explosion patch <NUM> attached to an outer side surface of the end cover <NUM> and covering the pressure relief mechanism <NUM>.

The anti-explosion patch <NUM> can be constructed as an insulating part and has a certain structural strength. By disposing the anti-explosion patch <NUM>, the leakage of the pressure relief mechanism <NUM> can be reduced. Moreover, by observing whether the anti-explosion patch <NUM> swells, it can be rapidly detected whether the pressure relief mechanism <NUM> is in an exhaust state. Or by observing whether the anti-explosion patch <NUM> swells when being not used normally, it is detected whether the pressure relief mechanism <NUM> is invalid.

With reference to <FIG>, a battery end cover assembly <NUM> according to an embodiment of the present application includes an end cover <NUM> and a liquid injection structure <NUM> disposed on the end cover <NUM>. The end cover <NUM> is an end sealing cover of a battery, the end cover <NUM> is provided with the liquid injection structure <NUM> by which an electrolyte can be injected into the battery, and after the electrolyte is injected, the end cover <NUM> is sealed by the liquid injection structure <NUM>.

As shown in <FIG>, the end cover <NUM> is provided with a liquid injection hole <NUM> penetrating in the thickness direction thereof. The battery end cover assembly <NUM> further includes a sealing nail <NUM> connected to the end cover <NUM> and covering the liquid injection hole <NUM>. By such disposing, it is convenient to inject a liquid via the liquid injection hole <NUM> during production, not only is the production flexible, but also the number of times of liquid injection and the liquid injection time can be selected as required. The electrolyte can be replenished in time when being found to be insufficient by detection, so that the reject ratio of the battery is reduced. When the production is completed, sealing is performed by using the sealing nail <NUM>, so that the sealing property is improved.

Specifically, a figured formed by an outer contour of the end cover <NUM> has a width median line L1, and distances from the width median line L1 to two opposite sides of the end cover <NUM> are the same. The liquid injection hole <NUM> is located in the width median line L1. By such disposing, when the liquid is injected into the liquid injection hole <NUM>, paths along which the injected electrolyte is infiltrated to two sides are approximately consistent, and the overall flow path of the electrolyte is relatively short, which is beneficial to the sufficient infiltration of electrode assemblies <NUM> on two sides in the electrolyte, thereby improving the overall liquid injection effect.

Further, as shown in <FIG>, the liquid injection hole <NUM> is located between one of the terminal assemblies <NUM> and the pressure relief mechanism <NUM>. Here, the position of the liquid injection hole <NUM> cannot be excessively deviated, and it is convenient to rapidly disperse the electrolyte to flow during liquid injection.

Optionally, the minimum distance between the liquid injection hole <NUM> and the pressure relief mechanism <NUM> is b3, the minimum distance between the liquid injection hole <NUM> and each of the terminal assemblies <NUM> is b4, and <NUM>≤b3/b4≤<NUM>. It can be understood that the end cover <NUM> on the position of the liquid injection hole <NUM> is relatively weak in structure; and by disposing the liquid injection hole <NUM> to be closer to the terminal assembly <NUM> and farther from the pressure relief mechanism <NUM>, on one hand, the situation that the liquid injection hole <NUM> is disposed to be too close to make the end cover <NUM> easy to deform here is avoided, on the other hand, the liquid injection hole <NUM> is protected to a certain extent by virtue of the structural strength of the terminal assembly <NUM>, the deformation of the end cover <NUM> on the position of the liquid injection hole <NUM> when the end cover <NUM> is impacted by a pressure is reduced, and thus, the overall structural strength is improved.

In some embodiments, as shown in <FIG>, a battery end cover assembly <NUM> includes an end cover <NUM>, terminal assemblies <NUM> and a pressure relief mechanism <NUM>, the terminal assemblies <NUM> and the pressure relief mechanism <NUM> are both disposed on the end cover <NUM>, and the end cover <NUM> is provided with a liquid injection structure <NUM>. The terminal assemblies <NUM>, the liquid injection structure <NUM> and the pressure relief structure <NUM> are disposed at intervals in the length direction of the end cover <NUM>, a figured formed by an outer contour of the end cover <NUM> has a width median line L1, and the terminal assemblies <NUM> and the pressure relief structure <NUM> are both disposed at intervals on the width median line L1.

The distances from the terminal assemblies <NUM> to two opposite sides of the end cover <NUM> are approximately consistent, during connection to other external components (such as a converging member), connection positions of the both are disposed in the center of the end cover <NUM> and are not excessively protruded to edges, which is beneficial to the protection for the connection reliability of connections. Particularly, when an external impact is generated, an impact force is not easily transferred to the connections of the terminal assemblies <NUM> and the other external components. The pressure relief mechanism <NUM> is further disposed on the width median line L1. Resistance borne when the pressure relief mechanism <NUM> relieves a pressure to two sides is approximately balanced, which is beneficial to smoother pressure relief.

With reference to <FIG> and <FIG>, a battery end cover assembly <NUM> according to an embodiment of the present application includes an end cover <NUM>, terminal assemblies <NUM>, a pressure relief mechanism <NUM> and an insulation board <NUM>, and the terminal assemblies <NUM> and the pressure relief mechanism <NUM> are both disposed on the end cover <NUM>. The end cover <NUM> is provided with an outer side surface <NUM> and an inner side surface <NUM> which are opposite in the thickness direction thereof, and the insulation board <NUM> is connected to the inner side surface <NUM> of the end cover <NUM>.

It can be understood that the inner side surface <NUM> of the end cover <NUM> refers to a surface, facing the inside of a battery, of the end cover <NUM>. That is, the battery end cover assembly <NUM> is internally provided with electrode assemblies <NUM>, and the inner side surface <NUM> of the end cover <NUM> is disposed to face the electrode assemblies <NUM>. The insulation board <NUM> is a component for separating the end cover <NUM> from the electrode assemblies <NUM> and is disposed on the side, facing the electrode assemblies <NUM>, of the end cover <NUM>, and the end cover <NUM> is insulated and isolated from the electrode assemblies <NUM> by the insulation board <NUM>. The insulation board <NUM> is made of an insulating material and may be made of a material such as plastics and rubber. Moreover, after the battery end cover assembly <NUM> includes the insulation board <NUM>, the end cover <NUM> is supported by the insulation board <NUM> so as to be improved in overall structural strength and not easy to deform and damage.

Specifically, as shown in <FIG>, the insulation board <NUM> is provided with first avoidance holes <NUM> corresponding to the terminal assemblies <NUM> and a second avoidance hole <NUM> corresponding to the pressure relief mechanism <NUM>. Therefore, the first avoidance holes <NUM> can facilitate electric connection between the terminal assemblies <NUM> and the electrode assemblies <NUM> therein, and the second avoidance hole <NUM> facilitates the impact of a gas to the pressure relief mechanism <NUM> via the second avoidance hole <NUM> during exhaust inside the battery.

As shown in <FIG>, the end cover <NUM> is provided with a liquid injection hole <NUM> penetrating in the thickness direction thereof. The battery end cover assembly <NUM> further includes a sealing nail <NUM> connected to the end cover <NUM> and covering the liquid injection hole <NUM>, and the insulation board <NUM> is provided with a third avoidance hole <NUM> corresponding to the liquid injection hole <NUM>, which aims at ensuring that an electrolyte can smoothly enter from the liquid injection hole <NUM> during liquid injection and flow to the electrode assemblies <NUM> via the third avoidance hole <NUM>. During liquid injection, there is a little interference from the insulation board <NUM>, the electrolyte flows more smoothly, and thus, the liquid injection efficiency can be increased. Furthermore, after the size and direction of the third avoidance hole <NUM> are reasonably set, the flow direction of the electrolyte can also be guided.

With reference to <FIG>, a battery end cover assembly <NUM> according to an embodiment of the present application includes an end cover <NUM>, terminal assemblies <NUM> and a pressure relief mechanism <NUM>, and the terminal assemblies <NUM> and the pressure relief mechanism <NUM> are both disposed on the end cover <NUM>.

As shown in <FIG>, each of the terminal assemblies <NUM> may include an electrode terminal <NUM> and a connecting piece <NUM>, the connecting piece <NUM> is a component for fixing the electrode terminal <NUM> to the end cover <NUM>, and the electrode terminal <NUM> is a component for outputting electric energy of a battery. There may be one or two terminal assemblies <NUM> on the end cover <NUM>.

In some embodiments, as shown in <FIG>, the two terminal assemblies <NUM> are provided and are respectively a positive terminal assembly <NUM> and a negative terminal assembly <NUM>, and the pressure relief mechanism <NUM> is located between the two terminal assemblies <NUM>. Therefore, positive and negative electrode connection with other external components (such as a converging member) can be performed on the battery end cover assembly <NUM>, positive and negative electrodes are centralized on the battery end cover assembly <NUM>, so that the integration level is high, and the overall wiring and layout of the battery are more compact, which is beneficial to the reduction of the overall volume.

Specifically, as shown in <FIG>, the distance between axes of the two terminal assemblies <NUM> is D1, the minimum distance between the axis of the negative terminal assembly <NUM> and an outer contour of the end cover <NUM> is D2, and <NUM>≤D1/D2≤<NUM>. After such disposing, the two terminal assemblies <NUM> can be reasonably distributed in the length direction of the end cover <NUM>, and the structural strength of the end cover <NUM> in a central area in the length direction can be improved, so that the deformation of the end cover <NUM> in the center is reduced, and the appearance and performance of the battery are improved.

With reference to <FIG>, a battery end cover assembly <NUM> according to an embodiment in a first aspect of the present application includes an end cover <NUM>, terminal assemblies <NUM> and a pressure relief mechanism <NUM>, and the terminal assemblies <NUM> and the pressure relief mechanism <NUM> are both disposed on the end cover <NUM>. The terminal assemblies <NUM> are used for internal and external electric energy transmission of a battery, and the pressure relief mechanism <NUM> is a component for relieving an internal pressure of the battery.

The pressure relief mechanism <NUM> and the terminal assemblies <NUM> are distributed at intervals in the length direction of the end cover <NUM>. The area of a figure formed by an outer contour of the end cover <NUM> is a first area S1, the area of a projection of the pressure relief mechanism <NUM> on the end cover <NUM> is a second area S2, and the second area S2 accounts for <NUM>% to <NUM>% of the first area S1. The pressure relief mechanism <NUM> and the terminal assemblies <NUM> are distributed at intervals in the length direction of the end cover <NUM>. The size of the pressure relief mechanism <NUM> in the length direction of the end cover <NUM> is b1 which is referred to as the length of the pressure relief mechanism <NUM>, and the length b1 of the pressure relief mechanism <NUM> accounts for <NUM>% to <NUM>% of the length b0 of the end cover <NUM>. The size of the pressure relief mechanism <NUM> in the width direction of the end cover <NUM> is e1 which is referred to as the width of the pressure relief mechanism <NUM>, and the width e1 of the pressure relief mechanism <NUM> accounts for <NUM>% to <NUM>% of the width e0 of the end cover <NUM>. Therefore, the pressure relief mechanism <NUM> can take up an area large enough for pressure relief and exhaust, thereby guaranteeing smooth and timely exhaust.

Meanwhile, each side, located on the pressure relief mechanism <NUM>, of the end cover <NUM> does not have to be set to be too narrow, so that the risk that the edge of the end cover <NUM> is easily fractured due to the overlarge length and width of the pressure relief mechanism <NUM> is avoided, and the situation that the end cover <NUM> is bent and fractured when bearing an impact and a pressure is avoided. Moreover, there is a sufficient space for arranging components on the end cover <NUM> so that all the components can be spaced without mutual interference. Furthermore, the structural strength of the end cover <NUM> can be guaranteed, excessive deformation caused when the end cover <NUM> bears a pressure is avoided, the probability that a gas is exhausted from the edge of the end cover <NUM> when the internal temperature or pressure of the battery is overhigh is avoided, it is ensured that the gas is only exhausted from the pressure relief mechanism <NUM>, the exhaust direction of the gas in the battery can be effectively controlled, it is convenient to perform subsequent treatment on exhausted electrolyte or high-temperature gas, and unwanted corrosion, fire hazards, etc. caused by arbitrary emission of the electrolyte or high-temperature gas in the battery are avoided.

As shown in <FIG>, the size of the pressure relief mechanism <NUM> in the length direction of the end cover <NUM> is b1, the minimum distance between the pressure relief mechanism <NUM> and each of the terminal assemblies <NUM> is b2, and b2>b1. By such disposing, the terminal assemblies <NUM> and other external components connected to the terminal assemblies <NUM> can be spaced from the pressure relief mechanism <NUM> by a sufficient distance. After the pressure relief mechanism <NUM> is opened, the pressure relief mechanism <NUM> is not easily blocked by the other external components, the probability that the internal gas and the electrolyte are ejected on the terminal assemblies <NUM> and the other external components when the pressure relief mechanism <NUM> performs pressure relief can be reduced, and the probability that the other external components catch fire is reduced. Moreover, after the pressure relief mechanism <NUM> is spaced from the terminal assemblies <NUM> for a safe distance, the risk of short circuit caused by conducting the positive and negative electrodes of the battery by an ejected material from the pressure relief mechanism <NUM> is not easily caused, and therefore, the safety of the battery can be improved.

As shown in <FIG> and <FIG>, the pressure relief mechanism <NUM> includes an anti-explosion valve <NUM>, and the anti-explosion valve <NUM> includes a preset opening area <NUM>. The preset opening area <NUM> is an area reserved for pressure relief when the anti-explosion valve <NUM> is designed. If pressure relief is required when the internal temperature or pressure of the battery is increased, the preset opening area <NUM> is opened, so that a pressure relief opening is formed in the anti-explosion valve <NUM>, and the gas in the battery is exhausted from the pressure relief opening formed after the preset opening area <NUM> is opened. For facilitating description, here, the outer edge of the preset opening area <NUM> is referred to as a predetermined open boundary <NUM>. The predetermined open boundary <NUM> is an edge contour of the pressure relief opening formed after the preset opening area <NUM> is opened.

Specifically, within the range of the tensile strength <NUM>-<NUM> N/mm<NUM> of the anti-explosion valve <NUM>, the tolerance pressure which can be borne by the anti-explosion valve <NUM> is approximately <NUM>-<NUM> MPa. Therefore, the tensile strength of the anti-explosion valve <NUM> should not be lower than <NUM> N/mm<NUM>, the tolerance pressure which can be borne by the anti-explosion valve <NUM> is prevented from being far lower than <NUM> MPa, and the situation that the anti-explosion valve <NUM> is opened due to partial temporary temperature or pressure rise inside the battery is avoided, so that the anti-explosion valve <NUM> cannot be damaged under reasonable temperature or pressure variation, and the error rate of the anti-explosion valve <NUM> is reduced. The tensile strength of the anti-explosion valve <NUM> should not be more than <NUM> N/mm<NUM>, and the tolerance pressure which can be borne by the anti-explosion valve <NUM> is prevented from being far more than <NUM> MPa, so that the situation that the anti-explosion valve <NUM> is still not opened when there is an explosion rise inside the battery is avoided, and it is ensured that the anti-explosion valve <NUM> can be opened in time for exhaust. An appropriate tensile strength is selected for the anti-explosion valve <NUM>, so that the anti-explosion valve <NUM> is not easily damaged during machining and assembling, and the production defect rate of the battery end cover assembly is reduced.

As shown in <FIG> and <FIG>, a section, perpendicular to the extension direction of the notch groove <NUM>, of the notch groove <NUM> is U-shaped or C-shaped. By adopting the U-shaped or C-shaped section, sharp corners on the contour of the notch groove <NUM> are reduced, the situation that the anti-explosion valve <NUM> generates overhigh centralized stresses on the weakest position is avoided, and thus, the probability that the anti-explosion valve <NUM> is opened on the position of a sharp corner due to overhigh centralized internal stresses is avoided. Therefore, by such disposing, the working reliability of the anti-explosion valve <NUM> can be improved.

Specifically, the contour line on the section, perpendicular to the extension direction of the notch groove <NUM>, of the notch groove <NUM> includes a circular arc line of which the radius r1 is <NUM>-<NUM>. Here, the radius r1 of the circular arc line is limited to be at least <NUM>, therefore, on one hand, it is easy to machine the circular arc contour, and on the other hand, centralized stresses generated here are effectively reduced. The radius r1 of the circular arc line is limited to be not greater than <NUM>, so that the depth of the notch groove <NUM> and the minimum thickness of the anti-explosion valve <NUM> on the position of the notch groove <NUM> can be reasonably distributed.

An energy storage apparatus 01A according to an embodiment in a second aspect of the present application includes the battery end cover assembly <NUM> according to the above-mentioned embodiment. For the energy storage apparatus 01A, by obtaining the battery end cover assembly <NUM> of which the area is matched with the pressure relief capacity, the smoothness of the anti-explosion pressure relief is guaranteed, meanwhile, the structural strength of the battery end cover assembly <NUM> is guaranteed, and thus, the use safety of the energy storage apparatus 01A is improved.

In the present application, the energy storage apparatus 01A is a single battery <NUM> as shown in <FIG> and <FIG>. A battery module 1000B is shown in <FIG> and a battery pack 1000C is shown in <FIG>.

The single battery <NUM> according to an embodiment of the present application, as shown in <FIG>, includes a housing <NUM>, electrode assemblies <NUM> and a battery end cover assembly <NUM>, the housing <NUM> is provided with an opening 200a, the electrode assemblies <NUM> are accommodated in the housing <NUM>, an end cover <NUM> of the battery end cover assembly <NUM> covers the opening 200a, and an inner side surface <NUM> of the end cover <NUM> is disposed to face the electrode assemblies <NUM>.

With reference to <FIG>, the housing <NUM> is a component for accommodating the electrode assemblies <NUM>, and the housing <NUM> may be of a hollow structure formed with an opening 200a in one end or a hollow structure formed with openings 200a in two ends. The housing <NUM> may be of various shapes such as a cylinder and a cuboid. The housing <NUM> may be made of various materials such as copper, iron, aluminum, steel and aluminum alloy.

There may be one or more electrode assemblies <NUM> in the housing <NUM>. For example, as shown in <FIG>, there are a plurality of electrode assemblies <NUM> which are stacked.

The battery end cover assembly <NUM> is an assembly covering the opening 200a of the housing <NUM> to insulate the internal environment of the single battery <NUM> from the external environment.

Specifically, the battery end cover assembly <NUM> includes an end cover <NUM>, terminal assemblies <NUM> and a pressure relief mechanism <NUM>, and the terminal assemblies <NUM> and the pressure relief mechanism <NUM> are both disposed on the end cover <NUM>. The area of a figure formed by an outer contour of the end cover <NUM> is a first area S1, the area of a projection of the pressure relief mechanism <NUM> on the end cover <NUM> is a second area S2, and the second area S2 accounts for <NUM>% to <NUM>% of the first area S1.

The single battery <NUM> according to an embodiment of the present application adopts the above-mentioned battery end cover assembly <NUM>, the area taken up by the pressure relief mechanism <NUM> on the end cover <NUM> is reasonably set, and there is a pressure relief opening large enough for exhaust after the pressure relief mechanism <NUM> is opened, so that the area of the end of the single battery <NUM> is relatively matched with the pressure relief capacity. In this way, the probability of untimely pressure relief is reduced, and the safety of the single battery <NUM> is improved. Moreover, the overall structural strength of the battery end cover assembly <NUM> can be guaranteed, and the battery end cover assembly is not easy to deform after bearing a pressure, so that the reliability of the overall single battery <NUM> can be improved.

It should be indicated that, in the present application, the single battery <NUM> 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., which is not limited in the embodiment of the present application. The single battery <NUM> may be cylindrical, flat, cuboid or in other shapes, which is not limited in the embodiment of the present application. The single battery <NUM> is generally divided into three types: a single cylinder battery, a single prismatic battery and a single pouch battery according to a packaging way, which is not limited either in the embodiment of the present application.

The housing <NUM> is internally provided with the electrode assemblies <NUM> and an electrolyte, and each of the electrode assemblies <NUM> is composed of a positive pole piece, a negative pole piece and an isolating membrane. The single battery <NUM> mainly works by virtue of the movement of metal ions between the positive pole piece and the negative pole piece. The positive pole piece includes a positive current collector and a positive active material layer, the positive active material layer is coated on the surface of the positive current collector, the positive current collector uncoated with the positive active material layer protrudes out of the positive current collector coated with the positive active material layer, and the positive current collector uncoated with the positive active material layer is used as a positive tab. With a lithium ion battery as an example, the positive current collector may be made of aluminum, and the positive active material layer may be lithium cobaltate, lithium ion phosphate, ternary lithium or lithium manganate, etc. The negative pole piece includes a negative current collector and a negative active material layer, the negative active material layer is coated on the surface of the negative current collector, the negative current collector uncoated with the negative active material layer protrudes out of the negative current collector coated with the negative active material layer, and the negative current collector uncoated with the negative active material layer is used as a negative tab. The negative current collector may be made of copper, and the negative active material layer may be carbon or silicon, etc. In order to guarantee the passing of a heavy current without fusing, there are a plurality of positive tabs stacked together, and there are a plurality of negative tabs stacked together. The isolating membrane may be made of PP (polypropylene) or PE (polyethylene), etc. Furthermore, each of the electrode assemblies <NUM> may be of a wound structure or a laminated structure, and embodiments of the present application are not limited thereto.

Further, for the development of a battery technology, design factors in various aspects such as energy density, cycle life, discharge capacity, charge-discharge rate and other performance parameters have to be taken into account.

As shown in <FIG>, in the single battery <NUM>, the battery end cover assembly <NUM> generally includes an end cover <NUM> and terminal assemblies <NUM>, as shown in <FIG>, each of the terminal assemblies <NUM> includes an electrode terminal <NUM> and a connecting piece <NUM>, the electrode terminal <NUM> is fixed to the end cover <NUM> via the connecting piece <NUM>, and the electrode terminal <NUM> is used to be electrically connected to the electrode assemblies <NUM> and is a component for outputting electric energy for the single battery <NUM>.

The ratio of the capacity a of the single battery <NUM> to the second area S2 is at least equal to <NUM>, wherein the unit of the capacity a is ampere·hour (A·H), and the unit of the second area S2 is square millimeter (mm<NUM>). In this way, the capacity a of the single battery <NUM> can be further reasonably matched with the area taken up by the pressure relief mechanism <NUM>.

Therefore, the pressure relief opening of the pressure relief mechanism <NUM> is relatively large, when abnormal conditions such as short circuit, overcharge and overdischarge occur to the single battery <NUM>, an internal pressure of the single battery <NUM> sharply rises, and when the pressure reaches a set anti-explosion air pressure point of the battery, the pressure relief mechanism <NUM> can be instantly opened to ensure that the gas inside the single battery <NUM> can be exhausted in time, prevent the single battery <NUM> from being exploded and play a role of instantly and completely leaking the gas, and thus, the anti-explosion purpose is achieved.

The battery module 1000B according to an example of the present application, as shown in <FIG>, includes a plurality of single batteries <NUM> which are arranged according to a certain sequence.

The battery pack 1000C according to an example of the present application, as shown in <FIG>, includes a box body <NUM> and a battery module 1000B, and the box body <NUM> is used for accommodating at least one battery module 1000B. The battery module 1000B is formed by arranging a plurality of single batteries <NUM>, and therefore, the battery pack 1000C includes the box body <NUM> and the plurality of single batteries <NUM>.

The box body <NUM> is a component for accommodating the single batteries <NUM>, provides an accommodating space for the single batteries <NUM> and may be of various structures. In some embodiments, the box body <NUM> may include a first part and a second part which are covered on each other to define an accommodating space for accommodating the single batteries <NUM>. The first part and the second part may be of various shapes such as a cuboid and a cylinder. The first part may be of a hollow structure opened in one side, the second part may also be of a hollow structure opened in one side, and the open side of the second part covers the open side of the first part to form the box body <NUM> with the accommodating space. Or, the first part is of a hollow structure opened in one side, the second part is of a plate-like structure, and the second part covers the open side of the first part to form the box body <NUM> with the accommodating space. The first part and the second part can be sealed by a sealing element which may be a sealing ring, a sealant, etc. The box body <NUM> can prevent liquid or other foreign matters from affecting the charge or discharge of the single batteries <NUM>.

In the battery pack 1000C, there may be one or more single batteries <NUM>. If there are a plurality of single batteries <NUM>, the plurality of single batteries <NUM> are in series connection or parallel connection or parallel-series connection, and the parallel-series connection means that the plurality of single batteries <NUM> are both in serial connection and parallel connection. It is possible that the plurality of single batteries <NUM> are in series connection or parallel connection or parallel-series connection to form the battery module 1000B firstly, and then, a plurality of battery modules 1000B are in series connection or parallel connection or parallel-series connection to form an integral whole to be accommodated in the box body <NUM>. Or, all the single batteries <NUM> are in direct series connection or parallel connection or parallel-series connection together, and then, the integral whole formed by all the single batteries <NUM> is accommodated in the box body <NUM>.

In some examples, the battery pack 1000C may further include a converging member by which the plurality of single batteries <NUM> can be electrically connected to achieve the series connection or parallel connection or parallel-series connection among of the plurality of single batteries <NUM>. The converging member may be a metal conductor such as copper, iron, aluminum, stainless steel and aluminum alloy.

Each of the plurality of single batteries <NUM> in the battery pack 1000C according to an embodiment of the present application adopts the above-mentioned battery end cover assembly <NUM>, and when being leaked during the assembly of the battery pack 1000C, a certain or some single batteries <NUM> can be rapidly recognized, so that the overhaul convenience of the battery pack 1000C can be improved.

The technical solutions described in the embodiments of the present application are applicable to the energy storage apparatus 01A and an electric device <NUM> with the energy storage apparatus 01A.

The electric device <NUM> may be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, an electric tool, etc. The vehicle may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a battery electric vehicle, a hybrid electric vehicle or a range-extended vehicle, etc.; the spacecraft includes an airplane, a rocket, an aerospace plane, a spaceship, etc.; the electric toy includes a fixed electric toy or a mobile electric toy, such as a game machine, an electric vehicle toy, an electric ship toy, an electric airplane toy, etc.; and the electric tool includes an electric metal cutting tool, an electric grinding tool, an electric assembling tool and an electric tool for a railway, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an electric impact drill, a concrete vibrator, an electric planer, etc. The above-mentioned electric device <NUM> is not specifically limited in the embodiment of the present application.

For facilitating description, the electric device <NUM> which is a vehicle is used as an example to be described in the following embodiment.

With reference to <FIG> which is a schematic view of a vehicle according to some embodiments of the present application, the vehicle is internally provided with an energy storage apparatus 01A which may be disposed on the bottom, head or tail of the vehicle. The energy storage apparatus 01A may be used for supplying power for the vehicle, for example, the energy storage apparatus 01A may be used as an operational power supply for the vehicle.

The electric device <NUM> according to an embodiment of the present application adopts the above-mentioned energy storage apparatus 01A, so that the working stability as well as reliability and safety of the electric device <NUM> can be improved.

The vehicle may further include a controller and a motor, and the controller is used for controlling the energy storage apparatus 01A to supply power for the motor, for example, it is used for meeting the demands on working power when the vehicle is started, navigated and driven.

In some embodiments of the present application, the energy storage apparatus 01A not only can be used as the operational power supply for the vehicle, but also can be used as a driving power supply for the vehicle to replace or partially replace fuel or natural gas to supply a driving force to the vehicle.

Claim 1:
An energy storage apparatus (01A), whereby the energy storage apparatus (01A) is a single battery (<NUM>), comprising a battery end cover assembly (<NUM>), the battery end cover assembly (<NUM>) comprising:
an end cover (<NUM>) of a rectangle;
terminal assemblies (<NUM>), the terminal assemblies (<NUM>) being connected to the end cover (<NUM>); and
a pressure relief mechanism (<NUM>), the pressure relief mechanism (<NUM>) being disposed on the end cover (<NUM>), and the pressure relief mechanism (<NUM>) and the terminal assemblies (<NUM>) being distributed at intervals in the length direction of the end cover (<NUM>);
wherein the area of a figure formed by an outer contour of the end cover (<NUM>) is a first area S1, the area of a projection of the pressure relief mechanism (<NUM>) on the end cover (<NUM>) is a second area S2, and the second area S2 accounts for <NUM>% to <NUM>% of the first area S1;
the size of the pressure relief mechanism (<NUM>) in the length direction of the end cover (<NUM>) is b1, and b1 accounts for <NUM>% to <NUM>% of the length b0 of the end cover (<NUM>); and
the size of the pressure relief mechanism (<NUM>) in the width direction of the end cover (<NUM>) is e1, and e1 accounts for <NUM>% to <NUM>% of the width e0 of the end cover (<NUM>);
wherein the pressure relief mechanism (<NUM>) comprises an anti-explosion valve (<NUM>), and the anti-explosion valve (<NUM>) comprises a preset opening area (<NUM>);
the anti-explosion valve (<NUM>) is provided with a notch groove (<NUM>), and the notch groove (<NUM>) is located in the preset opening area (<NUM>);
the minimum thickness of the anti-explosion valve (<NUM>) on the position of the notch groove (<NUM>) is a first thickness n1, the thickness of the anti-explosion valve (<NUM>) on the position of the preset opening area (<NUM>) is a second thickness n2, and the first thickness n1 accounts for <NUM>% to <NUM>% of the second thickness n2;
the tensile strength of the anti-explosion valve (<NUM>) is <NUM>-<NUM> N/mm<NUM>;
an area of the preset opening area (<NUM>) is at least a half of the second area S2 and not more than <NUM>% of the second area S2; and
a ratio (a/S2) of a capacity a of the energy storage apparatus (01A) to the second area (S2) is at least equal to <NUM>, wherein the unit of the capacity a is ampere-hour (AH), and the unit of the second area S2 is mm<NUM>.