CN220672712U - Battery cover plate and single battery - Google Patents

Abstract

The disclosure relates to the technical field of batteries, and discloses a battery cover plate and a single battery; the battery cover plate comprises a cover plate body, an explosion-proof piece, a first insulating piece and a second insulating piece; the cover plate body is provided with a first large surface and a second large surface which are oppositely arranged, and an explosion-proof through hole penetrating through the first large surface and the second large surface is formed in the cover plate body; the explosion-proof piece is arranged opposite to the explosion-proof through hole; the first insulating piece is arranged at least on one side of the first large surface, which is away from the cover plate body; the second insulating piece is arranged at least on one side of the second large surface, which is away from the cover plate body; the explosion-proof piece is connected with the first insulating piece and the second insulating piece to seal the explosion-proof through hole, and at least part of the explosion-proof piece, the first insulating piece and the second insulating piece are integrally formed injection structure. The battery cover plate increases the fixing strength of the explosion-proof piece, and prevents the explosion-proof piece from falling from the explosion-proof through hole so as to ensure the explosion-proof effect of the explosion-proof piece; the dual functions of the pressure-sensitive type explosion-proof valve and the temperature-sensitive type explosion-proof valve are integrated, so that the explosion-proof sheet can be timely exploded.

Description

Battery cover plate and single battery

Technical Field

The disclosure relates to the technical field of batteries, in particular to a battery cover plate and a single battery comprising the battery cover plate.

Background

At present, after the explosion-proof through hole is punched on the cover plate, an explosion-proof valve is formed in the explosion-proof through hole through injection molding, and the explosion-proof valve formed through injection molding can realize sealing of the explosion-proof through hole, but the explosion-proof valve is easy to fall off due to lower contact strength between the explosion-proof valve and the cover plate.

It should be noted that the information disclosed in the above background section is only for enhancing understanding of the background of the present disclosure and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

The disclosure aims to overcome the defect that an explosion-proof valve in the related art is easy to fall off, and provides a battery cover plate with the explosion-proof valve being difficult to fall off and a single battery comprising the battery cover plate.

According to one aspect of the present disclosure, there is provided a battery cover plate including:

the cover plate body is provided with a first large surface and a second large surface which are oppositely arranged, and an explosion-proof through hole penetrating through the first large surface and the second large surface is formed in the cover plate body;

the explosion-proof piece is arranged opposite to the explosion-proof through hole;

the first insulating piece is at least arranged on one side of the first large surface, which is away from the cover plate body;

the second insulating piece is at least arranged on one side of the second large surface, which is away from the cover plate body;

the explosion-proof piece is connected with the first insulating piece and the second insulating piece to seal the explosion-proof through hole, and at least part of the explosion-proof piece, the first insulating piece and the second insulating piece are of an integrally-formed injection structure.

According to the battery cover plate, the first insulating piece is at least arranged on one side of the first large surface, which is away from the cover plate body, the second insulating piece is at least arranged on one side of the second large surface, which is away from the cover plate body, and the explosion-proof piece is connected with the first insulating piece and the second insulating piece; the explosion-proof piece and at least part of the first insulating piece and the second insulating piece are of an integrally-formed injection molding structure. On the one hand, the explosion-proof piece is further fixed through the first insulating piece and the second insulating piece, so that the fixing strength of the explosion-proof piece is increased, the explosion-proof piece is prevented from falling off from the explosion-proof through hole, and the explosion-proof effect of the explosion-proof piece is ensured. On the other hand, the explosion-proof piece formed through injection molding can realize pressure opening and temperature opening, and the dual functions of the pressure-sensitive type explosion-proof valve and the temperature-sensitive type explosion-proof valve are integrated, so that the explosion-proof piece can be timely exploded. In yet another aspect, the rupture disc formed by injection molding has no stress concentration zone or no stress concentration zone of a conventional notched rupture valve, and the uniformity of the rupture disc cracking pressure is relatively easy to control.

According to another aspect of the present disclosure, there is provided a unit cell including:

the battery shell comprises a battery cover plate, and the battery cover plate is the battery cover plate;

and the battery core is arranged in the battery shell.

According to the single battery disclosed by the disclosure, the first insulating piece is at least arranged on one side of the first large surface, which is away from the cover plate body, the second insulating piece is at least arranged on one side of the second large surface, which is away from the cover plate body, and the explosion-proof piece is connected with the first insulating piece and the second insulating piece; the explosion-proof piece and at least part of the first insulating piece and the second insulating piece are of an integrally-formed injection molding structure. On the one hand, the explosion-proof piece is further fixed through the first insulating piece and the second insulating piece, so that the fixing strength of the explosion-proof piece is increased, the explosion-proof piece is prevented from falling off from the explosion-proof through hole, the explosion-proof effect of the explosion-proof piece is ensured, and the safety of the single battery is ensured. On the other hand, the explosion-proof piece formed through injection molding not only can realize pressure opening, but also can realize temperature opening, integrates the dual functions of the pressure-sensitive type explosion-proof valve and the temperature-sensitive type explosion-proof valve, so as to ensure that the explosion-proof piece can be exploded in time, and ensure the safety of the single battery. On the other hand, the explosion-proof piece formed by injection molding has no stress concentration area or the stress concentration area has no stress concentration of the traditional notch explosion-proof valve, so that the consistency of the opening pressure of the explosion-proof piece is easier to control, and the consistency of a plurality of single batteries is ensured; and the second insulating piece is located in the battery shell, so that the second insulating piece is closer to the battery cell, heat generated by the battery cell can be transferred to the explosion-proof piece and the first insulating piece through the second insulating piece, a heat conduction path is formed, and the heat dissipation capacity of the single battery is improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure. It will be apparent to those of ordinary skill in the art that the drawings in the following description are merely examples of the disclosure and that other drawings may be derived from them without undue effort.

Fig. 1 is a schematic partial cross-sectional view of a first example embodiment of a battery cover plate of the present disclosure.

Fig. 2 is a schematic partial cross-sectional view of a second example embodiment of a battery cover plate of the present disclosure.

Fig. 3 is a schematic partial cross-sectional view of a third example embodiment of a battery cover plate of the present disclosure.

Fig. 4 is a schematic partial cross-sectional view of a fourth example embodiment of a battery cover plate of the present disclosure.

Fig. 5 is a schematic partial cross-sectional view of a fifth example embodiment of a battery cover plate of the present disclosure.

Fig. 6 is a schematic perspective view of an exemplary embodiment of a battery cell according to the present disclosure.

Fig. 7 is a schematic view of a part of the battery cell of fig. 6 in cross section.

Reference numerals illustrate:

1. a cover plate body; 11. a first major surface; 111. a first step structure; 12. a second major surface; 121. a second step structure; 13. an explosion-proof through hole;

2. explosion-proof sheet; 21. a groove pattern; 22. reinforcing ribs;

3. a first insulating member;

4. a second insulating member; 41. a first portion; 42. a second portion; 421. a pole avoiding hole;

10. a battery cover plate;

20. a battery case; 201. a bottom plate; 202. a side plate;

30. a battery cell; 301. a tab; 40. a battery post;

x, first direction.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments can be embodied in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus detailed descriptions thereof will be omitted. Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of an icon to another component, these terms are used in this specification for convenience only, such as in terms of the orientation of the examples described in the figures. It will be appreciated that if the device of the icon is flipped upside down, the recited "up" component will become the "down" component. When a structure is "on" another structure, it may mean that the structure is integrally formed with the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

The terms "a," "an," "the," "said" and "at least one" are used to indicate the presence of one or more elements/components/etc.; the terms "comprising" and "having" are intended to be inclusive and mean that there may be additional elements/components/etc. in addition to the listed elements/components/etc.; the terms "first," "second," and "third," etc. are used merely as labels, and do not limit the number of their objects.

In the present application, unless explicitly specified and limited otherwise, the term "coupled" is to be construed broadly, and for example, "coupled" may be either fixedly coupled, detachably coupled, or integrally formed; can be directly connected or indirectly connected through an intermediate medium. "and/or" is merely an association relationship describing an association object, and means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

The present exemplary embodiment provides a battery cover 10, as shown with reference to fig. 1 to 5, the battery cover 10 including a cover body 1, a rupture disc 2, a first insulating member 3, and a second insulating member 4; the cover plate body 1 is provided with a first large surface 11 and a second large surface 12 which are oppositely arranged, and the cover plate body 1 is provided with an explosion-proof through hole 13 penetrating through the first large surface 11 and the second large surface 12; the explosion-proof sheet 2 is arranged opposite to the explosion-proof through hole 13; the first insulating piece 3 is arranged at least on one side of the first large surface 11, which faces away from the cover plate body 1; the second insulating piece 4 is arranged at least on one side of the second large surface 12, which faces away from the cover plate body 1; wherein, explosion proof piece 2 is connected with first insulating part 3 and second insulating part 4 in order to seal explosion proof through-hole 13, and explosion proof piece 2 and first insulating part 3 and second insulating part 4's at least part are integrated into one piece formula injection molding structure.

Based on the same inventive concept, the exemplary embodiments of the present disclosure provide a unit cell, which may include a cell case 20 and a battery cell 30, as shown with reference to fig. 6 and 7; the battery case 20 may include a battery cover 10, the battery cover 10 being any one of the battery cover 10 described below; the battery cell 30 is disposed within the battery housing 20.

The battery cover plate 10 and the single battery of the disclosure, on the one hand, the explosion-proof piece 2 is further fixed through the first insulating piece 3 and the second insulating piece 4, the fixing strength of the explosion-proof piece 2 is increased, the explosion-proof piece 2 is prevented from falling off from the explosion-proof through hole 13, the explosion-proof effect of the explosion-proof piece 2 is ensured, and the safety of the single battery is ensured. On the other hand, the explosion-proof piece 2 formed by injection molding can realize pressure opening and temperature opening, and integrates the dual functions of the pressure-sensitive explosion-proof valve and the temperature-sensitive explosion-proof valve, so that the explosion-proof piece 2 can be timely exploded, and the safety of a single battery is ensured. On the other hand, the explosion-proof sheet 2 formed by injection molding has no stress concentration area or the stress concentration area has no stress concentration of the traditional notched explosion-proof valve, so that the consistency of the opening pressure of the explosion-proof sheet 2 is easier to control, and the consistency of a plurality of single batteries is ensured; and the second insulating part 4 is located in the battery shell 20, so that the second insulating part 4 is closer to the battery cell 30, and heat generated by the battery cell 30 can be transferred to the explosion-proof piece 2 and the first insulating part 3 through the second insulating part 4, so that a heat conduction path is formed, and the heat dissipation capacity of the single battery is improved.

In the present exemplary embodiment, the unit cells may be quadrangular batteries, and thus, the battery case 20 may be provided in a rectangular parallelepiped structure. Specifically, the battery case 20 may include a battery cover plate 10, a bottom plate 201, and four side plates 202; the four side plates 202 are arranged in pairs; the four side plates 202 are connected end to end in order to form a rectangular parallelepiped cylinder. A battery cover plate 10 is connected to one side of the four side plates 202, and a bottom plate 201 is connected to the opposite side of the four side plates 202 such that the battery cover plate 10 is disposed opposite to the bottom plate 201. The battery cover 10, the bottom plate 201, and the four side plates 202 surround to form an accommodation space.

The material of the battery case 20 may be aluminum, steel, or other metal, alloy, or the like, but of course, other materials are also possible, and will not be described here.

Of course, in other example embodiments of the present disclosure, the bottom plate 201 and the battery cover plate 10 may be provided in a circular shape, an oval shape, a trapezoid shape, etc., and the side plates 202 may be provided in one or more and surround to form a circular shape, an oval shape, a trapezoid shape, etc., such that the battery case 20 is formed in a cylinder, an oval cylinder, a prism shape, etc.

In the present exemplary embodiment, referring to fig. 7, a battery cell 30 is disposed in a receiving cavity of a battery case 20, the battery cell 30 is configured as a rectangular parallelepiped to be fitted with the battery case 20, and the battery cell 30 may include a plurality of positive electrode tabs and negative electrode tabs (not shown in the drawings) stacked and disposed, and a separator disposed between the positive electrode tabs and the negative electrode tabs.

In this example embodiment, referring to fig. 6 and 7, the unit battery may further include a battery post 40, the battery post 40 may be connected to the battery cover 10, specifically, two post through holes are provided on the battery cover 10, the two battery posts 40 penetrate through the two post through holes in a one-to-one correspondence manner, and one battery post 40 is connected with the positive electrode tab of the battery cell 30 through the tab 301 to form the positive electrode of the unit battery, and the other battery post 40 is connected with the negative electrode tab of the battery cell 30 through the tab 301 to form the negative electrode of the unit battery. And the battery post 40 protrudes from the battery cover 10.

In the present exemplary embodiment, as shown with reference to fig. 1 to 5, the cap body 1 may be provided as a rectangular plate such that the cap body 1 may include two end surfaces disposed opposite to each other and four side surfaces connected between the two end surfaces. The areas of the two end surfaces are basically the same, and the areas of the two end surfaces are larger than the areas of the four side surfaces, so that the areas of the two end surfaces are the largest, and the two end surfaces are a first large surface 11 and a second large surface 12, so that the cover plate body 1 is provided with the first large surface 11 and the second large surface 12 which are oppositely arranged.

The cover plate body 1 is provided with an explosion-proof through hole 13 penetrating the first large surface 11 and the second large surface 12, that is, the cover plate body 1 is provided with an explosion-proof through hole 13 penetrating the cover plate body 1, and the explosion-proof through hole 13 can be circular, elliptical, rectangular, polygonal, semicircular, crescent or the like.

Of course, in other example embodiments of the present disclosure, the cap body 1 may be provided in other shapes according to the shapes of the unit cells; for example, the unit cells are cylindrical cells, and the cover plate body 1 is arranged in a circular shape; the single batteries are various prismatic batteries, and the cover plate body 1 is arranged into various polygons; the single battery is an elliptic cylinder battery, and the cover plate body 1 is arranged in an elliptic shape; not illustrated herein.

In the present exemplary embodiment, the explosion proof sheet 2 is disposed opposite the explosion proof through hole 13, specifically, the explosion proof sheet 2 is disposed directly opposite the explosion proof through hole 13. As shown with reference to fig. 1 and 2, the rupture disc 2 may be disposed within the rupture penetration hole 13 such that the rupture disc 2 is disposed opposite the rupture penetration hole 13. As shown in fig. 3 to 5, the explosion-proof sheet 2 may be disposed outside the explosion-proof through hole 13, but it is necessary that the explosion-proof sheet 2 is disposed opposite to the explosion-proof through hole 13.

At least on the side of the first large face 11 facing away from the cover plate body 1, a first insulating member 3 is provided, and as shown with reference to fig. 1 and 2, only on the side of the first large face 11 facing away from the cover plate body 1, a first insulating member 3 is provided, and the first insulating member 3 is provided in the shape of an annular plate. The first insulating member 3 is connected to the explosion-proof sheet 2, and specifically, an inner circumferential surface of the first insulating member 3 near the explosion-proof through hole 13 is integrally connected to the explosion-proof sheet 2.

At least on the side of the second large face 12 facing away from the cover plate body 1, a second insulating member 4 is provided, and as shown with reference to fig. 1 and 2, only on the side of the second large face 12 facing away from the cover plate body 1, the second insulating member 4 is provided, and the second insulating member 4 is also provided in the shape of an annular plate. The second insulating member 4 is connected to the explosion proof sheet 2, specifically, an inner circumferential surface of the second insulating member 4 near the explosion proof through hole 13 is integrally connected to the explosion proof sheet 2, so that the explosion proof sheet 2 is connected to the first insulating member 3 and the second insulating member 4 to seal the explosion proof through hole 13.

As shown with reference to fig. 3 to 5, the first insulating element 3 also extends into the explosion-proof through opening 13, so that the first insulating element 3 is not only arranged on the side of the first large face 11 facing away from the cover body 1; specifically, a portion of the first insulating member 3 covers the wall of the explosion-proof through hole 13 and is connected to the explosion-proof sheet 2 provided outside the explosion-proof through hole 13.

Of course, in other example embodiments of the present disclosure, it may be that the second insulating member 4 also extends into the explosion-proof through hole 13, such that the second insulating member 4 is not only provided on the side of the second large face 12 facing away from the cover plate body 1; specifically, a portion of the second insulating member 4 covers the wall of the explosion-proof through hole 13 and is connected to the explosion-proof sheet 2 provided outside the explosion-proof through hole 13.

Furthermore, the rupture disc 2 is integrally formed with at least part of the first insulating member 3 and the second insulating member 4 in an injection-molded structure; i.e. the rupture disc 2 is formed in one-piece with the first insulating member 3 and at least part of the second insulating member 4 by an injection moulding process.

The explosion-proof piece 2 is further fixed through the first insulating piece 3 and the second insulating piece 4, the fixing strength of the explosion-proof piece 2 is increased, and the explosion-proof piece 2 is prevented from falling off from the explosion-proof through hole 13, so that the explosion-proof effect of the explosion-proof piece 2 is ensured.

Moreover, the explosion-proof sheet 2 formed by injection molding not only can realize pressure opening (namely, the explosion-proof sheet 2 with the pressure exceeding a set value is cracked and exploded), but also can realize temperature opening (namely, the explosion-proof sheet 2 with the temperature exceeding the set value is melted and exploded), and the dual functions of the pressure-sensitive explosion-proof valve and the temperature-sensitive explosion-proof valve are integrated, so that the explosion-proof sheet 2 can be timely exploded. Furthermore, the explosion-proof sheet 2 formed by injection molding has no stress concentration area or the stress concentration area has no stress concentration of the traditional notch explosion-proof valve, and the consistency of the opening pressure of the explosion-proof sheet 2 is easier to control.

In some example embodiments, referring to fig. 2 and 7, the second insulator 4 may include a first portion 41 and a second portion 42; the first part 41 is connected with the explosion-proof sheet 2, and the first part 41 and the explosion-proof sheet 2 are of an integrally formed injection structure, namely, the first part 41 and the explosion-proof sheet 2 are of an integrally formed structure through an injection molding process; the second portion 42 and the first portion 41 are in a split structure, that is, the second portion 42 and the first portion 41 are two portions which are not connected, and the second portion 42 is fixed to the cover plate body 1.

A portion of the second insulating member 4 is fixed between the cap body 1 and the battery post 40, and specifically, a second portion 42 of the second insulating member 4 is fixed between the cap body 1 and the battery post 40.

Because the second portion 42 needs to be fixedly connected with the cover plate body 1 through the battery post 40, the fixing force when the battery post 40 fixes the second portion 42 is larger, if the second insulating piece 4 is of an integrated structure, the fixing force can be transmitted to the explosion-proof piece 2 through the second insulating piece 4, the strength of the explosion-proof piece 2 is lower, and the explosion-proof piece 2 cannot bear larger fixing force, so that the explosion-proof piece 2 is broken, and the explosion-proof effect cannot be achieved. The second insulating member 4 is separately provided as the first portion 41 and the second portion 42, so that the transmission of the fixing force generated when the second insulating member 4 is fixed to the explosion-proof sheet 2 can be reduced or even avoided, and the rupture of the explosion-proof sheet 2 is avoided, so that the explosion-proof effect of the explosion-proof sheet 2 is ensured.

Of course, in other example embodiments of the present disclosure, it may be that a portion of the first insulating member 3 is fixed between the cap body 1 and the battery post 40, and at the same time, a portion of the second insulating member 4 is fixed between the cap body 1 and the battery post 40; a part of the first insulating member 3 may be fixed between the cap body 1 and the battery post 40, or a part of the second insulating member 4 may be fixed between the cap body 1 and the battery post 40.

Further, the front projection of the first portion 41 onto the cover body 1 at least partially overlaps the front projection of the second portion 42 onto the cover body 1, i.e. the first portion 41 overlaps the second portion 42. For example, all of the front projection of the first portion 41 onto the cover body 1 may overlap with the front projection of the second portion 42 onto the cover body 1, or a part of the front projection of the first portion 41 onto the cover body 1 may overlap with a part of the front projection of the second portion 42 onto the cover body 1.

Moreover, in the case where the first portion 41 and the second portion 42 overlap, the second portion 42 is located on a side of the first portion 41 facing away from the cover body 1 at the overlapping position, for example, the second portion 42 may be covered on a side of the first portion 41 facing away from the cover body 1, or the second portion 42 may be covered on a portion of a side of the first portion 41 facing away from the cover body 1.

The first part 41 can be pressed through the second part 42, so that the first part 41 is prevented from being separated from the cover plate body 1, the fixing firmness of the explosion-proof sheet 2 is further improved, the explosion-proof sheet 2 is prevented from falling off, and the explosion-proof effect of the explosion-proof sheet 2 is ensured.

Referring to fig. 2, the thickness of the second portion 42 is greater than that of the first portion 41, so that a step can be arranged on one surface of the second portion 42, which is close to the cover plate body 1, and a part of the first portion 41, which is overlapped with the second portion 42, is located on the step surface, so that one surface of the second portion 42, which is close to the cover plate body 1, can be attached to the cover plate body 1, the fixing effect of the second portion 42 is ensured, and warping of the second portion 42 is avoided.

Referring to fig. 2, in the first direction X, the portion of the first portion 41 on the side of the second large face 12 facing away from the cover plate body 1 has a size K1, the rupture disc 2 has a size K2, and the ratio of K1 to K2 is 0.1 or more and 1.0 or less, for example, the ratio of K1 to K2 may be 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, or the like.

If the ratio of K1 to K2 is too large, the dimension K1 of the portion of the first portion 41 on the side of the second large face 12 facing away from the cover plate body 1 in the first direction X is too large, which increases the difficulty of the injection molding process and increases the cost.

If the ratio of K1 to K2 is too large, so that the dimension K1 of the portion of the first portion 41 on the side of the second large face 12 facing away from the cover plate body 1 in the first direction X is too small, it is difficult to fix the rupture disc 2 through the first portion 41, so that the rupture disc 2 is still easy to fall off and fails.

The above numerical range not only ensures that the process of injection molding can be easily implemented, but also ensures that the rupture disc 2 can be fixed through the first portion 41, and avoids the rupture disc 2 from falling off to fail.

Further, referring to fig. 2, in the first direction X, the portion of the first insulating member 3 on the side of the first large face 11 facing away from the cover plate body 1 has a size of K3, the size of the rupture disc is K2, the ratio of K3 to K2 is 0.1 or more and 1.0 or less, for example, the ratio of K3 to K4 may be 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, or the like.

If the ratio of K3 to K4 is too large, the dimension K3 of the portion of the first insulating member 3 located on the side of the first large face 11 facing away from the cover plate body 1 in the first direction X is too large, which increases difficulty of the injection molding process and increases cost.

If the ratio of K3 to K4 is too large, so that the dimension K3 of the portion of the first insulating member 3 located on the side of the first large face 11 facing away from the cover plate body 1 in the first direction X is too small, it is difficult to fix the rupture disk 2 through the first insulating member 3, so that the rupture disk 2 is still easy to fall off to fail.

The numerical range ensures that the explosion-proof sheet 2 can be fixed through the first insulating piece 3 and the explosion-proof sheet 2 is prevented from falling off to fail by the injection molding process.

Since the first large surface 11 is parallel to the second large surface 12, the first direction X is parallel to the second large surface 12, and the first direction X is also parallel to the first large surface 11. Further, the first direction X is a myriad of directions parallel to the first large surface 11 and the second large surface 12, and only one representative direction is shown in fig. 2.

In this exemplary embodiment, referring to fig. 7, a pole avoidance hole 421 is formed in the second portion 42, the pole avoidance hole 421 may be used to accommodate the battery pole 40, that is, the battery pole 40 may penetrate through the pole avoidance hole 421, and a portion of the second portion 42 is fixed between the cover plate body 1 and the battery pole 40, that is, the second portion 42 around the pole avoidance hole 421 is fixed between the cover plate body 1 and the battery pole 40, so that the second portion 42 is fixed with the battery pole 40 through the cover plate body 1.

Additionally, in other example embodiments of the present disclosure, the second insulator 4 may be of unitary construction, i.e., the second insulator 4 is of unitary construction; the area of the orthographic projection of the first insulating member 3 on the first reference surface is the same as the area of the orthographic projection of the second insulating member 4 on the first reference surface, that is, the first insulating member 3 and the second insulating member 4 are arranged as large, and the shape of the first insulating member 3 and the shape of the second insulating member 4 may be the same, and the first reference surface is parallel to the first large surface 11. The preparation process is simpler.

In some example embodiments, the thickness of a portion of the first insulating member 3 away from the rupture disc 2 is greater than the thickness of a portion of the first insulating member 3 near the rupture disc 2, in particular, it may be that the thickness of the first insulating member 3 increases with increasing distance from the rupture disc 2 such that the thickness of the first insulating member 3 is set to be gradual; it is also possible to divide the first insulating member 3 in two parts, including a part remote from the rupture disc 2 and a part close to the rupture disc 2, the thickness of the part remote from the rupture disc 2 being greater than the thickness of the part close to the rupture disc 2.

Since a portion of the first insulating member 3 away from the explosion-proof sheet 2 receives a pressing force or an impact force during the assembly of the battery cover plate, if the thickness is too thin, breakage occurs easily, and thus the thickness of the portion of the first insulating member 3 away from the explosion-proof sheet 2 is set thicker, breakage due to the pressing force or the impact force can be avoided.

The thickness of a portion of the second insulating member 4 away from the rupture disk 2 is greater than the thickness of a portion of the second insulating member 4 near the rupture disk 2, and in particular, may be such that the thickness of the second insulating member 4 increases with increasing distance from the rupture disk 2, so that the thickness of the second insulating member 4 is set to be gradual; it is also possible to divide the second insulating member 4 in two parts, comprising a part remote from the rupture disc 2 and a part close to the rupture disc 2, the thickness of the part remote from the rupture disc 2 being greater than the thickness of the part close to the rupture disc 2.

Since a portion of the second insulating member 4 away from the explosion-proof sheet 2 receives a pressing force or an impact force during the assembly of the battery cover plate, if the thickness is too thin, breakage occurs easily, and thus the thickness of the portion of the second insulating member 4 away from the explosion-proof sheet 2 is set thicker, breakage due to the pressing force or the impact force can be avoided.

It should be noted that the division of the first insulating member 3 into two parts and the division of the second insulating member 4 into two parts are merely different thickness divisions, and the two parts of the first insulating member 3 are also integrally formed, and the two parts of the second insulating member 4 are also integrally formed.

In the present exemplary embodiment, at least portions of the rupture disc 2, the first insulating member 3 and the second insulating member 4 are integrally formed nano injection molded structures, that is, at least portions of the rupture disc 2, the first insulating member 3 and the second insulating member 4 are integrally formed by a nano injection molding process, for example, the rupture disc 2, the first insulating member 3 and the first portion 41 are integrally formed nano injection molded structures.

Nano injection molding refers to nano molding technology (NMT, nano Molding Technology), which is a technology of combining metal and plastic with nano technology, namely, after the metal surface is subjected to nanocrystallization, the plastic is directly injection molded on the metal surface, so that the metal and the plastic can be integrally molded, and finally combined into a product. The term "nano" as used herein refers to a microporation process, i.e. a process of carrying out nano-scale microporation on a metal surface by a specific solution, and the main purpose is to better combine the metal surface with plastic and improve the connection strength.

Moreover, the nano injection molding process can achieve injection molding on a metal (e.g., aluminum or steel) of 0.2mm or more, and can achieve efficient design of an explosion-proof structure on the thin cap plate or the thin battery case 20. I.e., the explosion-proof sheet 2 can be formed on the cap plate or the battery case 20 having a thickness of 0.2mm through a nano injection molding process. The battery case 20 is suitable for the single battery with thinner thickness at present, and is beneficial to improving the energy density of the single battery.

Furthermore, the nano injection molding process can realize one-die multi-cavity forming, and can greatly improve the assembly and production efficiency of cover plate manufacture, thereby improving the assembly and production efficiency of single batteries.

At least part of the materials of the explosion-proof sheet 2, the first insulating member 3 and the second insulating member 4 can be common polymer plastics such as PPS (polyphenylene sulfide), PP (polypropylene), LCP (liquid crystal polymer), PEEK (polyether ether ketone), PET (polyethylene terephthalate) and the like, can be some plastic composites, and can be modified by properly adding glass fiber, mineral powder or other materials. These materials are abundant in productivity and inexpensive, thereby contributing to cost reduction.

In the present exemplary embodiment, the thickness of the rupture disc 2 is 0.2mm or more and 3 mm or less, for example, the thickness of the rupture disc 2 may be 0.5 mm, 0.7 mm, 1 mm, 1.3 mm, 1.5 mm, 1.8 mm, 2mm, 2.2 mm, 2.5 mm, 2.7 mm, or the like.

If the thickness of the explosion-proof sheet 2 is too thick, the explosion-proof sheet 2 cannot be exploded in time under the set pressure or the set temperature, so that the explosion of the single battery is caused. If the thickness of the explosion-proof sheet 2 is too thin, the explosion-proof sheet 2 is exploded before reaching the set pressure or the set temperature, and the service life of the single battery is affected.

The numerical range enables the explosion-proof sheet 2 to be exploded in time under the set pressure or the set temperature, and the explosion-proof effect and the service life of the explosion-proof sheet 2 are ensured.

Further, referring to fig. 2, the thickness of the rupture disc 2 is H1, the distance between the side of the first insulating member 3 away from the cover plate body 1 and the side of the second insulating member 4 away from the cover plate body 1 is H2, and the ratio of H1 to H2 is 0.2 or more and 1 or less, for example, the ratio of H1 to H2 may be 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, or the like.

If the ratio of H1 to H2 is too small, the thickness of the explosion-proof sheet 2 is too small, the explosion-proof sheet 2 is easy to damage, and the explosion-proof requirement cannot be met. If the ratio of H1 to H2 is too large, the thickness of the explosion-proof sheet 2 is too large, and under the condition that the battery cell 30 is overheated, the explosion-proof sheet 2 cannot be exploded rapidly, so that the single battery explodes, and a safety accident is caused.

The numerical range not only ensures that the explosion-proof sheet 2 is not easy to damage, but also can meet the explosion-proof requirement; and the explosion-proof sheet 2 can be ensured to be exploded rapidly, so that safety accidents are avoided.

Further, referring to fig. 1 and 3, the thickness of the rupture disc 2 may be uniform throughout such that when a set pressure or temperature is reached within the battery case 20, the rupture disc 2 bursts throughout substantially simultaneously, forming a large channel, allowing the overheated gas to be discharged in time.

Of course, as shown with reference to fig. 4, the thickness of the explosion-proof sheet 2 may be increased with an increase in the distance from the wall of the explosion-proof through hole 13, i.e., the explosion-proof sheet 2 may be made thinner at the middle thicker edge portion. So set up, when reaching settlement pressure or temperature in battery case 20, the marginal portion of explosion-proof piece 2 explodes at first, and marginal portion explodes for explosion-proof piece 2 wholly breaks away from with apron body 1, thereby makes explosion-proof piece 2 wholly explode, forms great passageway, makes and in time discharges through the heat gas.

In addition, the specific structure of the rupture disc 2 is not limited to the above description, and in some exemplary embodiments of the present disclosure, as shown in fig. 2, when the overall thickness of the rupture disc 2 is set to be thick, the rupture disc 2 may be provided with a groove pattern 21, and the groove pattern 21 may be a cross-shaped groove, or may be a structure of two opposite circular arc grooves. Of course, the groove pattern 21 may have other structures, which are not described herein. When the set pressure or temperature is reached in the battery case 20, the groove pattern 21 on the explosion-proof sheet 2 is exploded first, so that the explosion-proof sheet 2 is exploded integrally, and the overheat gas can be discharged in time.

In the case where the entire thickness of the rupture disk 2 is set to be thin, as shown in fig. 5, the rupture disk 2 may be provided with the reinforcing ribs 22. The reinforcing ribs 22 may be cross-shaped reinforcing ribs 22 or grid-shaped reinforcing ribs 22. Of course, the reinforcing ribs 22 may have other structures, which are not described herein. When the set pressure or temperature is reached in the battery case 20, the position of the explosion-proof sheet 2, where the reinforcing ribs 22 are not arranged, is exploded first, so that the explosion-proof sheet 2 is exploded integrally, and the overheat gas can be discharged in time.

Referring to fig. 3 to 5, the first large face 11 may include a first stepped structure 111, and the first stepped structure 111 is disposed around the explosion-proof through hole 13, i.e., the first stepped structure 111 surrounding the explosion-proof through hole 13 is disposed at a position of the first large face 11 near the explosion-proof through hole 13. Referring to fig. 3 and 4, the first step structure 111 may include one step surface. Referring to fig. 5, the first step structure 111 may include two step surfaces, and the two step surfaces are disposed opposite to each other such that the first step structure 111 forms a convex ring structure.

Of course, in other example embodiments of the present disclosure, the first step structure 111 may include two, three, or more step surfaces, and the two, three, or more step surfaces may be disposed on the same side, forming a gradually increasing or decreasing structure; three or more step surfaces may also be disposed in opposition to form a progressively higher and progressively lower convex ring structure.

The first insulating member 3 covers at least part of the first step structure 111, i.e. the first insulating member 3 may cover a part of the first step structure 111, or the first insulating member 3 may cover all of the first step structure 111. The firmness of fixing the first insulating member 3 can be further increased through the first step structure 111, so that the firmness of fixing the explosion-proof sheet 2 is increased, the explosion-proof sheet 2 is prevented from falling off from the explosion-proof through hole 13, the explosion-proof effect of the explosion-proof sheet 2 is ensured, and the safety of the single battery is ensured.

Referring to fig. 3 to 5, the second large surface 12 may include a second stepped structure 121, and the second stepped structure 121 is disposed around the explosion-proof through hole 13, i.e., the second stepped structure 121 surrounding the explosion-proof through hole 13 is disposed at a position of the second large surface 12 near the explosion-proof through hole 13. Referring to fig. 3-5, the second step structure 121 may include a step surface.

Of course, in other example embodiments of the present disclosure, the second step structure 121 may include two, three, or more step surfaces, and the two, three, or more step surfaces may be disposed on the same side, forming a gradually increasing or decreasing structure; the two step surfaces may also be disposed opposite to each other, so that the second step structure 121 forms a convex ring structure; three or more step surfaces may also be disposed in opposition to form a progressively higher and progressively lower convex ring structure.

The second insulating member 4 covers at least part of the second step structure 121, i.e. the second insulating member 4 may cover a part of the second step structure 121, and the second insulating member 4 may cover all of the second step structure 121. The firmness of the fixation of the second insulating member 4 can be further increased through the second step structure 121, so that the firmness of the fixation of the explosion-proof sheet 2 is increased, the explosion-proof sheet 2 is prevented from falling off from the explosion-proof through hole 13, the explosion-proof effect of the explosion-proof sheet 2 is ensured, and the safety of the single battery is ensured.

In addition, in other example embodiments of the present disclosure, the first step structure 111 surrounding the explosion-proof through hole 13 may be provided only at a position of the first large face 11 near the explosion-proof through hole 13, and the second step structure 121 surrounding the explosion-proof through hole 13 may not be provided at a position of the second large face 12 near the explosion-proof through hole 13. It is also possible that only the second large face 12 is provided with the second step structure 121 surrounding the explosion-proof through hole 13 at a position close to the explosion-proof through hole 13, and the first step structure 111 surrounding the explosion-proof through hole 13 is not provided at a position close to the explosion-proof through hole 13 at the first large face 11.

The weakest area of the rupture disc 2 of the present disclosure is larger in size than the prior art rupture valve having a scored structure provided on the metal battery case 20, and the accuracy and complexity are not as high as the prior art rupture valve, and the nano injection mold is far cheaper than the prior art rupture valve mold. Thereby reducing the manufacturing cost of the rupture disc 2 and thus the cost of the unit cell.

Moreover, by changing the material and thickness of the explosion-proof sheet 2, the explosion pressure and the explosion temperature of the explosion-proof sheet 2 can be controlled, and the pressure and temperature range coverage is wider, so that the explosion-proof sheet is suitable for single batteries with different rated capacities.

Specifically, for example, the explosion pressure of the explosion-proof sheet 2 may be 0.4MPa or more and 1.2MPa or less, and for example, the explosion pressure of the explosion-proof sheet 2 may be 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa, 0.9MPa, 1.0MPa, 1MPa, or the like. Moreover, the control accuracy may be within.+ -. 0.15 MPa.

The explosion temperature of the explosion-proof sheet 2 may be 80 ℃ or higher and 180 ℃ or lower, for example, the explosion temperature of the explosion-proof sheet 2 may be 85 ℃, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, 125 ℃, 130 ℃, 135 ℃, 140 ℃, 145 ℃, 150 ℃, 155 ℃, 160 ℃, 165 ℃, 170 ℃, 175 ℃, or the like. Moreover, the control accuracy may be within.+ -. 10 ℃.

The terms "parallel" and "perpendicular" as used in this application may not only be perfectly parallel, perpendicular, but may also have some error; for example, the included angle between the two is greater than or equal to 0 ° and less than or equal to 5 °, i.e. the two are considered to be parallel to each other; the included angle between the two is more than or equal to 85 degrees and less than or equal to 95 degrees, namely the two are considered to be mutually perpendicular.

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

Claims (15)

1. A battery cover plate, comprising:

the cover plate body is provided with a first large surface and a second large surface which are oppositely arranged, and an explosion-proof through hole penetrating through the first large surface and the second large surface is formed in the cover plate body;

the explosion-proof piece is arranged opposite to the explosion-proof through hole;

the first insulating piece is at least arranged on one side of the first large surface, which is away from the cover plate body;

the second insulating piece is at least arranged on one side of the second large surface, which is away from the cover plate body;

the explosion-proof piece is connected with the first insulating piece and the second insulating piece to seal the explosion-proof through hole, and at least part of the explosion-proof piece, the first insulating piece and the second insulating piece are of an integrally-formed injection structure.

2. The battery cover plate of claim 1, wherein the second insulator comprises:

the first part is connected with the explosion-proof sheet and is integrally formed into an injection molding structure with the explosion-proof sheet;

the second part and the first part are of a split structure, and the second part is fixed on the cover plate body.

3. The battery cover of claim 2, wherein an orthographic projection of the first portion onto the cover body at least partially overlaps an orthographic projection of the second portion onto the cover body, and wherein the second portion is located on a side of the first portion facing away from the cover body at the overlap.

4. The battery cover plate of claim 3, wherein the thickness of the second portion is greater than the thickness of the first portion.

5. The battery cover plate of claim 2, wherein in a first direction, a dimension of a portion of the first portion on a side of the second major surface facing away from the cover plate body is K1, a dimension of the rupture disk is K2, a ratio of K1 to K2 is 0.1 or more and 1.0 or less, and the first direction is parallel to the second major surface.

6. The battery cover plate of claim 2, wherein the second portion is provided with a post relief hole for receiving a battery post, and a portion of the second portion is secured between the cover plate body and the battery post.

7. The battery cover plate of claim 1, wherein the second insulator is of unitary construction, the area of orthographic projection of the first insulator on the first datum plane is the same as the area of orthographic projection of the second insulator on the first datum plane, and the first datum plane is parallel to the first major surface.

8. The battery cover of any one of claims 1-7, wherein a portion of the first insulator remote from the rupture disc has a thickness greater than a portion of the first insulator proximate to the rupture disc, and a portion of the second insulator remote from the rupture disc has a thickness greater than a portion of the second insulator proximate to the rupture disc.

9. The battery cover plate of any one of claims 1-7, wherein at least a portion of the rupture disc, the first insulator, and the second insulator are integrally formed as a nano-injection molded structure.

10. The battery cover plate according to any one of claims 1 to 7, wherein the thickness of the explosion-proof sheet is 0.2mm or more and 3 mm or less.

11. The battery cover plate according to any one of claims 1 to 7, wherein the thickness of the explosion-proof sheet is H1, the distance between the side of the first insulating member away from the cover plate body and the side of the second insulating member away from the cover plate body is H2, and the ratio of H1 to H2 is 0.2 or more and 1 or less.

12. The battery cover plate according to any one of claims 1 to 7, wherein the thickness of the rupture disc is uniform throughout, or the thickness of the rupture disc increases with increasing distance from the wall of the explosion-proof through hole.

13. The battery cover plate according to any one of claims 1 to 7, wherein the explosion-proof sheet is provided with a groove pattern or a reinforcing rib.

14. A single cell, characterized by comprising:

a battery case comprising a battery cover plate, the battery cover plate being the battery cover plate according to any one of claims 1 to 13;

and the battery cell is arranged in the battery shell.

15. The cell defined in claim 14, wherein the battery further comprises:

and the battery pole is connected with the cover plate body, a part of the first insulating piece is fixed between the cover plate body and the battery pole, and/or a part of the second insulating piece is fixed between the cover plate body and the battery pole.