CN220492121U - Explosion-proof valve, top cap subassembly and battery - Google Patents

Abstract

The application provides an explosion-proof valve, a top cover assembly and a battery, and relates to the technical field of energy storage; the explosion-proof sheet comprises a first surface and a second surface which are oppositely arranged along the thickness direction of the explosion-proof sheet; a part of the first surface is recessed towards the second surface to form a groove; the buffer part is arranged at the bottom of the groove and/or is arranged in the area of the second surface opposite to the groove; the buffer portion is configured to release stress generated by the internal gas pressure of the battery to the rupture disk. By the arrangement, the explosion-proof valve can be prevented from being exploded in advance, and the safety of the battery is improved.

Description

Explosion-proof valve, top cap subassembly and battery

Technical Field

The application relates to the technical field of energy storage, in particular to an explosion-proof valve, a top cover assembly and a battery.

Background

A battery, which is a device for converting chemical energy into electric energy, is widely used in the fields of new energy automobiles, energy storage power stations, and the like, and generally includes a battery case, and an electrode assembly and an electrolyte provided in the battery case.

In the related art, a battery case generally includes a case having an opening, and a top cover covering the opening; the top cover is provided with a liquid injection hole and an explosion-proof valve. In the manufacturing and using process of the battery, certain air pressure can be generated in the battery and acts on the inside of the whole battery, and because the explosion-proof valve is arranged on the battery, the whole explosion-proof valve surface bears the action of the air pressure, when the air pressure value reaches the pressure relief critical value of the explosion-proof valve, the thinnest part of the explosion-proof valve is cracked and exploded to release the air pressure in the battery, the explosion of the battery is prevented, and the safety of the battery is improved. However, when the explosion-proof valve does not reach the critical value of pressure relief, the explosion-proof valve is easy to be opened in advance by explosion, so that the cost of the battery is lost and even safety accidents are caused.

Disclosure of Invention

The embodiment of the application provides an explosion-proof valve, top cap subassembly and battery for solve explosion-proof valve and open in advance, the technical problem that security performance is low.

A first aspect of embodiments of the present application provides an explosion-proof valve, including an explosion-proof sheet and a buffer portion; the explosion-proof sheet comprises a first surface and a second surface which are oppositely arranged along the thickness direction of the explosion-proof sheet; a portion of the first surface is recessed toward the second surface to form a groove;

the buffer part is arranged at the bottom of the groove and/or is arranged in the area of the second surface opposite to the groove; the buffer is configured to release the pressure of the battery interior from stressing the rupture disk.

In an alternative embodiment, the buffer portion includes stress relief grooves and/or ribs, and the depth of the stress relief grooves is smaller than the thickness of the explosion-proof sheet at the position corresponding to the groove.

In an alternative embodiment, the rupture disc further comprises a score groove provided on the groove bottom of the stress relief groove and/or the second surface; when the notch groove is arranged on the second surface, the notch groove and the stress relief groove are arranged in an aligned mode, and the notch groove and the stress relief groove form an opening part.

In an alternative embodiment, the number of the opening parts is at least two, at least two opening parts intersect, and the intersection point of at least two opening parts forms an explosion starting point.

In an alternative embodiment, the number of the opening parts is two;

the distance between the two end parts of one opening part is smaller than the length of the groove passing through the two end parts;

the distance between the opposite ends of the two opening portions is smaller than the width of the groove passing through the opposite end positions.

In an alternative embodiment, a cross section parallel to the rupture disc is taken as a cross section; the cross-sectional area of the explosion-proof piece is larger than that of the groove;

the cross-sectional area of the groove is larger than the cross-sectional area of the stress relief groove;

the cross-sectional area of the groove is larger than the cross-sectional area of the score groove;

the cross-sectional area of the stress relief groove is equal to or greater than the cross-sectional area of the score groove.

In an alternative embodiment, the sum of the depth of the stress relief groove and the depth of the score groove and the thickness of the rupture disc at the location corresponding to the groove range from 0.02mm to 5mm.

In an alternative embodiment, a preset included angle is formed between the bottom of the notch groove and the groove wall.

In an alternative embodiment, the explosion proof valve further comprises a protective protrusion disposed on the first surface and surrounding the recess.

A second aspect of embodiments of the present application provides a cap assembly comprising a cap and the explosion proof valve of the first aspect;

the top cover is provided with a mounting groove, the mounting groove comprises a first mounting groove and a second mounting groove, the second mounting groove is arranged below the first mounting groove, and the width of the second mounting groove is smaller than that of the first mounting groove;

the explosion-proof valve is installed in the first installation groove, and the top surface of the explosion-proof valve protrudes out of the top surface of the top cover.

A third aspect of embodiments of the present application provides a battery comprising the cap assembly of the second aspect.

According to the explosion-proof valve, the top cover assembly and the battery, the buffer part is arranged at the bottom of the groove and/or the area of the second surface opposite to the groove; when the explosion-proof piece is impacted by the internal air pressure of the battery, the buffer part can release the internal air pressure of the battery to the stress of the explosion-proof piece, so that the deformation degree of the explosion-proof piece is reduced, the explosion-proof valve is further prevented from being opened and exposed in advance, the cost loss of the battery is avoided, and the safety of the battery is improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application.

Fig. 1 is a schematic structural diagram of a battery according to an embodiment of the present disclosure;

FIG. 2 is a top view of a top cover provided in an embodiment of the present application;

FIG. 3 is a cross-sectional view taken along the line A-A in FIG. 2;

fig. 4 is a schematic structural view of a top cover and an explosion-proof valve according to an embodiment of the present disclosure;

FIG. 5 is a cross-sectional view taken along the direction B-B in FIG. 4;

FIG. 6 is an enlarged schematic view of region C of FIG. 5;

FIG. 7 is a top view of a header assembly provided in an embodiment of the present application;

FIG. 8 is a cross-sectional view taken along the direction D-D in FIG. 7;

FIG. 9 is an exploded view of the header assembly provided in an embodiment of the present application;

FIG. 10 is a top view of a first embodiment of an explosion protection valve provided herein;

FIG. 11 is a cross-sectional view taken along the line E-E of FIG. 10;

FIG. 12 is an enlarged schematic view of region G of FIG. 11;

FIG. 13 is a cross-sectional view taken along the direction F-F in FIG. 10;

FIG. 14 is a second cross-sectional view taken along the direction E-E in FIG. 10;

FIG. 15 is an enlarged schematic view of region H of FIG. 14;

FIG. 16 is a partial schematic view of a stress relief groove and score groove provided in an embodiment of the present application;

FIG. 17 is a schematic view of a stress relief groove and score groove provided in an embodiment of the present application;

fig. 18 is a schematic structural view of an explosion-proof sheet according to an embodiment of the present application;

FIG. 19 is a second top view of an explosion protection valve provided in an embodiment of the present application;

FIG. 20 is a top view III of an explosion protection valve provided in an embodiment of the present application;

fig. 21 is a schematic view of an explosion-proof valve provided in an embodiment of the present application subjected to internal air pressure.

Reference numerals illustrate:

100: an explosion-proof valve; 110: explosion-proof sheet; 111: a first surface; 112: a second surface; 120: a buffer section; 121: a first edge; 122: a second edge; 130: a groove; 131: a bending region; 132: the side wall of the groove; 140: a scoring groove; 141: the groove bottom of the notch groove; 142: the groove wall of the notch groove; 150: an opening surface; 160: a protective protrusion;

200: a top cover; 210: a mounting groove; 211: a first mounting groove; 212: a second mounting groove; 220: a liquid injection hole; 230: a first mounting hole; 231: a first plastic packaging layer; 232: a first seal ring; 240: a second mounting hole; 241: a second plastic packaging layer; 242: a second seal ring; 250: a positive electrode post; 260: a negative electrode column; 270: a third plastic packaging layer;

300: a housing;

400: and a battery cell.

Specific embodiments thereof have been shown by way of example in the drawings and will herein be described in more detail. These drawings and the written description are not intended to limit the scope of the inventive concepts in any way, but to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments.

Detailed Description

As described in the background art, the explosion-proof valve in the related art has a problem of early explosion opening. The inventor researches and discovers that the problem is caused by the fact that when the internal air pressure of the battery reaches a certain value, the air pressure can impact the explosion-proof piece of the explosion-proof valve, so that the explosion-proof valve starts to slightly deform and bulge or sink, the internal air pressure of the battery does not reach a critical value, the thinnest part of the explosion-proof valve is exploded and opened in advance, the cost loss of the battery and even a safety accident are caused, and the safety of the battery is reduced.

In view of the above technical problems, embodiments of the present application provide an explosion-proof valve, a top cap assembly, and a battery, by providing a buffer portion at a bottom of a groove, and/or on an area of a second surface opposite to the groove; when the explosion-proof piece is impacted by the internal air pressure of the battery, the buffer part can release the stress of the internal air pressure of the battery to the explosion-proof piece, so that the deformation degree of the explosion-proof piece is reduced, the explosion-proof valve is further prevented from being opened and exposed in advance, the cost loss of the battery is avoided, and the safety of the battery is improved.

In order to make the above objects, features and advantages of the embodiments of the present application more comprehensible, the following description will make the technical solutions of the embodiments of the present application clear and complete with reference to the accompanying drawings in the embodiments of the present application. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present application.

The embodiment of the application provides a battery which can be applied to an electric device and provides electric energy for the electric device. The electric device in the embodiment of the application may be a vehicle, for example: the vehicle can be a fuel oil vehicle, a fuel gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extending vehicle and the like.

In addition, the device may be other energy storage devices, such as a mobile phone, a portable device, a notebook computer, an electric toy, an electric tool, a ship, a spacecraft, etc., where the spacecraft may include an airplane, a rocket, a space plane, or a spacecraft.

Referring to fig. 1, the battery may include a case 300, a battery cell 400, and a top cap assembly. Wherein, the casing has holding chamber and with holding chamber intercommunication's open-top. The accommodating cavity is used for accommodating the battery cell and the electrolyte. Illustratively, the cells may be mounted into the receiving cavity through a top opening.

The cap assembly is disposed on the housing 300 and covers at the top opening. Wherein the cap assembly includes an explosion proof valve 100 and a cap 200. Referring to fig. 2 and 3, the top cover 200 is provided with a mounting groove 210 and a filling hole 220, the mounting groove 210 and the filling hole 220 are disposed on the top cover 200 at intervals, and the mounting groove 210 and the filling hole 220 penetrate through the top cover 200 along the thickness direction of the top cover 200. Note that, the thickness direction of the top cover 200 may refer to the Z direction in fig. 3.

The mounting groove 210 includes a first mounting groove 211 and a second mounting groove 212, and the second mounting groove 212 is disposed below the first mounting groove 211 and communicates with the first mounting groove 211. The notch of the first mounting groove 211 is the top surface of the top cover 200, and the notch of the second mounting groove 212 is the bottom surface of the top cover 200.

Referring to fig. 4 to 6, the width of the second mounting groove 212 is smaller than the width of the first mounting groove 211, so that a portion of the bottom of the first mounting groove 211 is used as a bearing surface of the explosion proof valve 100, for example, a portion of the bottom of the explosion proof valve 100 contacts with the bottom of the first mounting groove 211.

In the process of preparing the head cover assembly, the explosion-proof valve 100 may be first installed in the first installation groove 211, and the support for the explosion-proof valve 100 may be provided by the groove bottom of the first installation groove 211. Thereafter, the explosion-proof valve 100 is fixed in the first mounting groove 211 by means of welding sealing. The welding sealing mode comprises laser pulse welding, laser continuous welding and the like. In one example, the manner of welding the seal is laser continuous welding, thus ensuring maximum quality effect of the weld. The welding seam has the shape of semicircle, sharp triangle, trapezoid, double wave crest and column. In an example, the shape of the welding seam is semicircular, sharp triangle or columnar, and the arrangement effectively ensures the firmness and the tightness of the welding seam.

As an example, with continued reference to fig. 3, the thickness of the top cover 200 may be denoted as T _Top The depth of the first mounting groove 211 may be denoted as T ₁ The rupture disk 110 has a thickness T _{Anti-theft device} . Depth T of first mounting groove 211 ₁ Less than the thickness T of the top cover 200 _Top Greater than the thickness T of the rupture disc 110 _{Anti-theft device} Thus, the assemblability of the explosion-proof valve 100 and the top cover 200 can be satisfied. Exemplary, 0.3 mm.ltoreq.T _{Anti-theft device} ≤T ₁ ≤T _Top 10mm or less, the depth T of the first mounting groove 211 is set to ensure the maximization of the yield and productivity ₁ Is positioned at 0.3 mm-2.0 mm.

In this embodiment, referring to fig. 2 and fig. 7 to 9, the top cover 200 is further provided with a first mounting hole 230 and a second mounting hole 240. The first mounting hole 230 is provided at a side of the filling hole 220 facing away from the mounting groove 210. The first mounting hole 230 is internally provided with the positive electrode post 250, and two ends of the positive electrode post 250 are respectively positioned outside the first mounting hole 230 along the thickness direction of the top cover 200, so that the positive electrode post 250 is electrically connected with an external power supply, and the positive electrode post 250 is electrically connected with the battery cell 400.

A first plastic layer 231 and a first sealing ring 232 are arranged between the first mounting hole 230 and the positive electrode post 250, and the first plastic layer 231 and the first sealing ring 232 can ensure tightness between the first mounting hole 230 and the positive electrode post 250.

The second mounting hole 240 is provided on a side of the mounting groove 210 facing away from the pour hole 22. The second mounting hole 240 is internally provided with the negative electrode post 260, and along the thickness direction of the top cover 200, two ends of the negative electrode post 260 are respectively positioned outside the second mounting hole 240, so that the negative electrode post 260 is electrically connected with an external power supply, and the negative electrode post 260 is electrically connected with the battery cell 400.

A second plastic sealing layer 241 and a second sealing ring 242 are arranged between the second mounting hole 240 and the negative electrode post 260, and the second plastic sealing layer 241 and the second sealing ring 242 can ensure tightness between the second mounting hole 240 and the negative electrode post 260.

The third plastic layer 270 is disposed on the surface of the top cover 200 facing the battery cell 400, and the third plastic layer 270 is used for removing the positive electrode post 250 and the negative electrode post 260, and other parts are electrically insulated from the battery cell 400.

It should be noted that, the positions of the third plastic layer 270 and the injection hole 220, and the positions of the third plastic layer 270 and the mounting groove 210 may be provided with through holes.

Referring to fig. 10 to 21, the explosion proof valve 100 includes an explosion proof sheet 110; along the thickness direction of the rupture disc 110, the rupture disc 110 includes a first surface 111 and a second surface 112 disposed opposite to each other, the second surface 112 facing the housing 300. Taking the orientation shown in fig. 11 as an example, the first surface 111 is the upper surface of the rupture disc 110 and the second surface 112 is the lower surface of the rupture disc 110.

A portion of the first surface 111 is recessed toward the second surface 112 to form a recess 130. The groove 130 is a countersink, and the bottom of the groove 130 is located inside the rupture disc 110.

The perpendicular distance between the bottom of the groove 130 and the second surface 112 in the thickness direction of the rupture disc 110 is T4, which is used to characterize the weak area of the rupture disc 110. In order to characterize the vertical distance T4 between the bottom of the recess 130 and the second surface 112, the thickness T of the explosion-proof valve 100 is not limited _{Anti-theft device} And (5) performing comparison. For example, the vertical distance between the bottom of the groove 130 and the second surface 112 is T ₄ Less than the thickness T of the explosion proof valve 100 _{Anti-theft device} In one embodiment, the vertical distance between the bottom of the groove 130 and the second surface 112 is T ₄ And thickness T of explosion proof valve 100 _{Anti-theft device} The values of (2) are all in the range of 0-10mm, that is, 0 < T ₄ ＜T _{Anti-theft device} And < 10mm. Wherein T is more than 0.01 ₄ /T _{Anti-theft device} And 1, the manufacturability of the explosion-proof valve 100 and the structural strength of the explosion-proof valve 100 can be ensured. Exemplary, 0.3 < T ₄ /T _{Anti-theft device} ≤0.7。

It should be noted that the shape of the bottom of the groove 130 and the second surface 112 opposite to the bottom of the groove 130 may be selected in various ways. For example, referring to fig. 18, the shape of the bottom of the groove 130 and the second surface 112 opposite to the bottom of the groove 130 may include a plane, an arcuate surface protruding away from the first surface 111, or an arcuate surface protruding toward the first surface 111.

The explosion proof valve 100 further includes a buffer portion 120, the buffer portion 120 being disposed at a bottom of the groove 130 and/or on an area of the second surface 112 opposite to the groove 130. When the explosion-proof piece is impacted by the internal air pressure of the battery, the buffer part can release the internal air pressure of the battery to the stress of the explosion-proof piece, so that the deformation degree of the explosion-proof piece is reduced, the explosion-proof valve is further prevented from being opened and exposed in advance, the cost loss of the battery is avoided, and the safety of the battery is improved.

Referring to fig. 11-13, in one possible implementation, the cushioning portion 120 includes stress relief grooves and/or ribs. As an example, the buffer 120 includes a stress relief groove provided on the bottom of the groove 130, and may be provided on an area of the second surface 112 corresponding to the groove 130. Referring to fig. 21, when the internal air pressure of the battery impacts the explosion-proof plate, the stress release groove can absorb and release the stress of the internal air pressure of the battery to the explosion-proof plate 110, so as to reduce the deformation degree of the explosion-proof plate 110, further prevent the explosion-proof valve 100 from being opened and exposed in advance, avoid the cost loss of the battery and improve the safety of the battery.

The depth of the stress relief groove is less than the thickness of the rupture disc 110 at the location corresponding to the recess 130. Referring to fig. 12, the thickness of the explosion-proof sheet 110 at the corresponding position of the recess 130, i.e. the vertical distance between the bottom of the recess 130 and the second surface 112, T in fig. 12 ₄ . The depth of the stress relief groove is T ₂ ，T ₂ Less than T ₄ And T is ₄ The range of the value of (2) is 0-5mm.

The dimension in the X direction shown in fig. 12 is marked as the width, the width of the stress release groove is W1, and the range of W1 is 0-10mm, so that the explosion-proof valve can be ensured to be opened and blasted in time, and the yield of production and preparation can be ensured.

In the present embodiment, the section in the thickness direction of the explosion-proof sheet 110 is a longitudinal section, and the longitudinal section shape of the stress relief groove is a circular arc, a trapezoid, or a square. The longitudinal section of the stress release groove is preferably trapezoidal, so that the timely release of the stress of the air pressure applied to the explosion-proof valve 100 and the accuracy of the explosion value can be relieved to the greatest extent.

As another example, the buffer 120 includes a reinforcing rib (not shown) provided at the bottom of the groove 130 and/or on an area of the second surface 112 corresponding to the groove 130. The reinforcing ribs can increase the structural strength of the explosion-proof sheet 110, increase the deformation resistance of the explosion-proof sheet 110, reduce the deformation degree of the explosion-proof sheet 110, further prevent the explosion-proof valve 100 from being opened and exposed in advance, avoid the cost loss of the battery and improve the safety of the battery.

As yet another example, the buffer 120 includes both stress relief grooves and reinforcing ribs. The stress relief groove and the reinforcing rib may be provided at the bottom of the groove 130 at the same time; or may be disposed on the second surface 112 at the same time in the region corresponding to the recess 130; it is also possible that stress relief grooves are provided on the bottom of the groove 130, and reinforcing ribs are provided in the region of the second surface 112 corresponding to the groove 130; alternatively, stress relief grooves are provided in the second surface 112 in the region corresponding to the grooves 130, and reinforcing ribs are provided on the bottoms of the grooves 130. In this example, the buffer portion 120 includes both a stress relief groove and a reinforcing rib, so that the deformation resistance of the explosion-proof valve 100 can be improved to the greatest extent, the explosion-proof valve 100 is prevented from being opened and exposed in advance, the cost loss of the battery is avoided, and the safety of the battery is improved.

With continued reference to fig. 10-16, the rupture disc further includes a score groove 140. In one possible implementation, score groove 140 is provided on the groove bottom and/or second surface 112 of the stress relief groove. When the score groove 140 is disposed on the second surface 112, the score groove 140 is disposed in alignment with the stress relief groove, i.e., the score groove 140 is disposed directly below the stress relief groove; at this time, the thickness of the rupture disc 110 located under the stress relief groove may be thinned such that the stress relief groove and the score groove 140 constitute the weakest area of the rupture disc 110, thereby constituting the opening portion of the rupture disc 110.

When the internal air pressure of the battery reaches a limit value, for example, when the internal air pressure of the battery reaches a critical value for opening the explosion-proof valve 100, the opening part of the explosion-proof valve 100 receives impact force, and the explosion is opened to release the pressure, so that the safety of the battery is improved.

In one possible implementation, the rupture disc 110 further includes a score groove 140, the score groove 140 being disposed on the second surface 112 and offset from the stress relief groove. That is, the projection of the stress relief groove onto the second surface 112 does not coincide with the score groove 140. Thus, the function of the notch groove 140 is similar to that of the stress release groove, when the internal air pressure of the battery impacts the explosion-proof piece, the notch groove 140 can absorb the stress of the internal air pressure of the battery to the explosion-proof piece 110, the stress of the internal air pressure of the battery to the explosion-proof piece 110 can be released, the deformation degree of the explosion-proof piece 110 is reduced, the explosion-proof valve 100 is further prevented from being opened and exposed in advance, the cost loss of the battery is avoided, and the safety of the battery is improved.

In this embodiment, referring to fig. 12, the sum of the depth of the stress relief groove and the depth of the score groove 140 is smaller than the thickness of the explosion-proof sheet 110 corresponding to the groove 130, and the difference between the sum of the depth of the stress relief groove and the depth of the score groove 140 and the thickness of the explosion-proof sheet 110 corresponding to the groove 130 is in the range of 0.02mm-5mm.

Referring to fig. 12, the thickness of the explosion-proof sheet 110 corresponding to the groove 130 is the thickness T between the bottom of the groove 130 and the second surface 112 ₄ . The depth of the stress relief groove is T ₂ Score groove 140 has a depth T ₅ 。T ₂ And T ₅ The sum is less than T ₄ 。

In this embodiment, the difference between the thickness of the corresponding position of the rupture disc 110 and the groove 130 and the sum of the depth of the stress relief groove and the depth of the score groove 140 is the thickness of the weakest area of the rupture disc 110, i.e. T in FIG. 12 ₃ . Wherein T is ₃ In the range of 0.02mm to 5mm, T being exemplary ₃ The value range of (2) is 0.2mm, so that the explosion-proof valve 100 can be opened and blasted in time, and the stability of the explosion-proof valve 100 and the yield of production are maximum.

In one possible implementation, referring to fig. 15 and 16, the groove bottom 141 of the score groove and the groove wall 142 of the score groove have a predetermined angle therebetween. The preset included angle can be an acute angle or an obtuse angle. That is, the preset included angle α has a value ranging from 0 ° to 180 °, but excluding the right angle 90 °. Preferably, the preset included angle alpha is in the range of 95-180 degrees, so that the explosion-proof valve 100 can be effectively ensured to be opened in time.

Referring to fig. 17, in the present embodiment, the cross-sectional shape of the score groove 140 may be V-shaped, arc-shaped, trapezoid-shaped, square-shaped; illustratively, the cross-sectional shape of the score groove 140 is trapezoidal, the width of the notch of the score groove 140 is W2, the groove bottom width of the score groove 140 is W3, the width of the notch of the score groove 140 is W2 greater than the groove bottom width of the score groove 140 is W3, which are both less than the width of the stress relief groove W1. Wherein the width of the stress relief groove is W1, and the range of the value is 0-10mm, including the maximum endpoint value.

By such arrangement, the timely release of the stress of the air pressure applied to the explosion-proof valve 100 and the accuracy of the explosion value can be relieved to the greatest extent.

In one possible embodiment, the cross-section is taken as a cross-section parallel to the rupture disc 110; taking the orientation shown in fig. 10 as an example, the shape of the stress relief groove and the shape of the score groove 140 shown in fig. 10 are each of a cross-sectional shape.

Wherein the cross-sectional area of the rupture disc 110 is greater than the cross-sectional area of the recess 130; the cross-sectional area of the groove 130 is greater than the cross-sectional area of the stress relief groove; the cross-sectional area of groove 130 is greater than the cross-sectional area of score groove 140; the cross-sectional area of the stress relief groove is equal to or greater than the cross-sectional area of the score groove 140.

In the present embodiment, for convenience of describing the dimensions of the buffer portion 120 and the score groove 140 in detail, the cross-sectional area of the rupture disc may be denoted as S1, that is, the area of the second surface 112 is S1. The cross-sectional area of the groove 130 is S2, i.e., the groove bottom area of the groove 130 is S2. The cross-sectional area of the stress relief groove is S3, that is, the groove bottom area of the stress relief groove is S3, and the cross-sectional area of the notch groove 140 is S4, wherein S1 is greater than S2, S2 is greater than S3, S2 is greater than S4, and S3 is greater than or equal to S4.

In an example, the cross-sectional shapes of the rupture disc 110 and the groove 130 are in a kidney-shaped structure, wherein the cross-sectional area S1 of the rupture disc 110 is equal to the sum of the rectangular area and the two semicircular areas, and accordingly, the cross-sectional area S2 of the groove 130 is equal to the sum of the rectangular area and the two semicircular areas.

The cross-sectional shape of the stress relief groove and score groove 140 is circular arc. The stress release groove is provided with a first edge 121 and a second edge 122 which are oppositely arranged in the width direction Y of the explosion-proof sheet, the centers of the first edge 121 and the second edge 122 are concentrically arranged, the radius of the first edge 121 is R1, the fan-shaped area where the first edge 121 is positioned is equal to 2R1+L1, and L1 is the arc length of the first edge 121; the radius of the second edge 122 is R2, the fan-shaped area of the second edge 122 is equal to 2r2+l2, where L2 is the arc length of the second edge 122, and the cross-sectional area S3 of the stress relief groove is equal to (2r2+l2) - (2r1+l1).

Accordingly, the calculation manner of the cross-sectional area S4 of the score groove 140 is the same as that of the cross-sectional area S3 of the stress relieving groove, and the description thereof is omitted herein.

In one possible implementation, the opening portion separates the rupture disc 110 into at least two opening surfaces. For example, referring to fig. 19, the number of opening portions is one, and the opening portions divide the rupture disc 110 into two opening surfaces 150. For another example, referring to fig. 10, the number of openings is two, and the two openings intersect to separate the rupture disc 110 into four opening surfaces 150. The intersection point of the two opening parts forms an explosion starting point, when the internal air pressure of the battery reaches the pressure relief critical value when the explosion-proof valve 100 is opened, the opening parts of the explosion-proof valve 100 are subjected to impact force, the intersection points of the two opening parts are preferentially exposed, and then the explosion-proof valve is split along the extending direction of the opening parts, so that the internal air pressure of the battery is discharged outside the battery, and the safety of the battery is improved.

In addition, the explosion-starting point formed by the intersection point of the two opening parts coincides with the geometric center point of the groove 130, so that the explosion-proof valve 100 is exploded and opened from the middle weak part, the pressure release value of the explosion-proof valve 100 from the middle deformation part is fed back more accurately, the real-time receipt inside the battery is convenient to collect and master, the service life of the battery is analyzed by the system, the cost of the battery is reduced, and the safety of the battery is improved

In one possible implementation, with continued reference to fig. 10 and 20, the number of opening portions is two, and the two opening portions are symmetrically disposed with respect to the length direction of the rupture disc 110. That is, the two opening portions are symmetrically arranged with respect to the X direction. By means of the arrangement, the area of the explosion-proof sheet 110 corresponding to the groove 130 can be reasonably divided into four opening surfaces 150, and further, the stress can be timely released when the explosion-proof valve 100 is deformed, and the explosion value of the explosion-proof valve 100 can be ensured to be in a proper range.

In this embodiment, the explosion valve 100 has an open burst value of 0.1MPa to 10.0MPa. Illustratively, the explosion valve 100 has an opening explosion value of 0.3Mpa to 3.0Mpa, which can prevent the explosion valve from being exploded in advance when the air pressure does not reach the critical value, and can prevent the safety accident caused by untimely explosion when the air pressure exceeds the critical value too much.

The shape of each opening may be selected from a variety of shapes, for example, the projected shape of each opening on the second surface 112 may be a straight line, an arc line, or a combination of straight and arc lines. When the projection shape of the opening portion on the second surface 112 is a combination of a straight line and an arc line, the number of the straight line and the arc line may be plural, and the plural straight lines and the plural arc lines are alternately and sequentially connected, for example, two adjacent straight lines are connected by one arc line. As one example, each opening portion is projected in a circular arc shape on the second surface 112. When the explosion-proof valve 100 is opened, the explosion point can be opened quickly, the stress is released in time, and the safety of the battery is improved.

Referring to fig. 20, in one possible implementation, the end of the opening portion is a predetermined distance from the sidewall 132 of the recess. The left and right end portions of the opening portion have a certain interval with the side wall of the groove 130 in the X direction, so that the length of the opening portion in the X direction is smaller than the length of the groove 130; the left and right end portions of the opening portion have a certain interval from the side wall of the groove 130 in the Y direction so that the width of the opening portion in the Y direction is smaller than the width of the groove 130.

In other words, the distance between the two ends of one of the opening portions is smaller than the length of the groove 130 passing through the two end positions; that is, in fig. 20, the value of L1 is smaller than the value of L2 so that the left and right end portions of the opening portion have a certain distance from the side wall of the recess 130 in the X direction.

The distance between the opposite ends of the two opening portions is smaller than the width of the recess 130 passing through the opposite end positions. That is, in fig. 20, the value of L3 is smaller than the value of L4 so that the left and right end portions of the opening portion have a certain distance from the side wall of the recess 130 in the Y direction.

So set up, the region between the tip of opening portion and the lateral wall of recess 130 constitutes the region of buckling 131, and after explosion-proof valve 100 blasting, opening surface 150 turns over for the region of buckling 131, prevents to follow recess 130's edge fracture between the opening surface 150, avoids opening surface 150 to fly away, has improved the security of battery.

It should be noted that, the bending region 131 in this embodiment may be understood as a region between the dotted line and the sidewall of the groove 130 in fig. 14.

In the present embodiment, the difference between the length of the opening portion in the X direction and the length of the groove 130 is 0.5mm. The difference between the width of the opening portion in the Y direction and the width of the groove 130 is 0.5mm. By the arrangement, the pressure of the explosion-proof valve 100 can be discharged in time after pressure relief, and the opening surface 150 cannot fly out after explosion, so that the safety of the battery is improved. Wherein, the length of the groove 130 refers to the maximum value of the length of the groove 130 in the X direction, and the width of the groove 130 refers to the maximum value of the width of the groove 130 in the Y direction.

In one possible implementation, referring to fig. 11, the explosion proof valve 100 further includes a shielding protrusion 160, the shielding protrusion 160 being disposed on the first surface 111 and surrounding the recess 130. That is, the shielding protrusion 160 has a ring-shaped structure and is disposed around the groove 130. So set up, the protection protruding 160 can keep off in the outside of recess 130, and when the electrolyte that overflows via annotating the liquid hole 220 flows and flows to protection protruding 160 department along the surface of top cap 200, protection protruding 160 can play the barrier function, avoids the electrolyte that overflows from annotating the liquid hole 220 to flow to in the recess 130 of explosion-proof piece 110, prevents corrosion of explosion-proof piece 110, has improved explosion-proof valve 100's life and battery's security.

In addition, the protection protrusion 160 further improves the structural strength of the rupture disc 110, reduces the deformation degree of the rupture disc 110, and improves the capability of the rupture disc 110 to resist external mechanical pulling and extrusion, thereby improving the safety performance of the explosion-proof valve 100.

In this embodiment, the number of the guard protrusions 160 may be one or more. When the number of the shielding protrusions 160 is plural, the shielding protrusions 160 are disposed at intervals in a direction away from the recess 130, that is, the shielding protrusions 160 sequentially surround the recess 130 and are disposed at intervals. By this arrangement, the structural strength of the rupture disk 110 can be improved as much as possible.

The longitudinal section of the protection protrusion 160 is circular arc, square or trapezoid with the section perpendicular to the rupture disc 110 as the longitudinal section. Illustratively, the shield projections 160 have a square or trapezoidal longitudinal cross-sectional shape. By the arrangement, electrolyte can be effectively prevented from overflowing into the explosion-proof valve 100, and the safety performance of the explosion-proof valve 100 is improved.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the application pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It is to be understood that the present application is not limited to the precise arrangements and instrumentalities shown in the drawings, which have been described above, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims (11)

1. An explosion-proof valve is characterized by comprising an explosion-proof sheet and a buffer part; the explosion-proof sheet comprises a first surface and a second surface which are oppositely arranged along the thickness direction of the explosion-proof sheet; a portion of the first surface is recessed toward the second surface to form a groove;

the buffer part is arranged at the bottom of the groove and/or is arranged in the area of the second surface opposite to the groove; the buffer portion is configured to release stress generated by the internal gas pressure of the battery to the explosion-proof sheet.

2. The explosion-proof valve according to claim 1, wherein the buffer portion comprises a stress relief groove and/or a reinforcing rib, and the depth of the stress relief groove is smaller than the thickness of the explosion-proof sheet at the position corresponding to the groove.

3. The explosion protection valve of claim 2, wherein said explosion protection sheet further comprises a score groove disposed on a groove bottom of said stress relief groove and/or said second surface; when the notch groove is arranged on the second surface, the notch groove and the stress relief groove are arranged in an aligned mode, and the notch groove and the stress relief groove form an opening part.

4. The explosion valve of claim 3, wherein the number of said opening portions is at least two, at least two of said opening portions intersect, and the intersection of at least two of said opening portions forms an explosion initiation point.

5. The explosion-proof valve according to claim 4, wherein the number of the opening portions is two;

the distance between the two end parts of one opening part is smaller than the length of the groove passing through the two end parts;

the distance between the opposite ends of the two opening portions is smaller than the width of the groove passing through the opposite end positions.

6. The explosion protection valve according to any one of claims 3 to 5, wherein a cross section parallel to the explosion protection plate is taken as a cross section;

the cross-sectional area of the explosion-proof piece is larger than that of the groove;

the cross-sectional area of the groove is larger than the cross-sectional area of the stress relief groove;

the cross-sectional area of the groove is larger than the cross-sectional area of the score groove;

the cross-sectional area of the stress relief groove is equal to or greater than the cross-sectional area of the score groove.

7. The explosion proof valve of claim 6, wherein a difference between a sum of a depth of the stress relief groove and a depth of the score groove and a thickness of the explosion proof sheet at a position corresponding to the groove ranges from 0.02mm to 5mm.

8. The explosion protection valve according to any one of claims 3 to 5, wherein a predetermined angle is formed between the groove bottom and the groove wall of the score groove.

9. The explosion protection valve of any one of claims 1-5, further comprising a protective protrusion disposed on the first surface and disposed around the recess.

10. A cap assembly comprising a cap and the explosion valve of any one of claims 1-9;

the top cover is provided with a mounting groove, the mounting groove comprises a first mounting groove and a second mounting groove, the second mounting groove is arranged below the first mounting groove, and the width of the second mounting groove is smaller than that of the first mounting groove;

the explosion-proof valve is installed in the first installation groove, and the top surface of the explosion-proof valve protrudes out of the top surface of the top cover.

11. A battery comprising the cap assembly of claim 10.