Battery monomer and battery pack

Abstract

The utility model relates to the technical field of new energy batteries, and discloses a single battery and a battery pack, the single battery is provided with a first direction, and the single battery comprises a shell, a first electrode, a second electrode and a third electrode, the electrode assembly is arranged in the accommodating cavity; the anti-explosion valve is fixedly connected with the shell and seals and covers the pressure relief hole; the insulating film comprises a bottom surface film and a side surface film connected with the bottom surface film, the bottom surface film and the side surface film enclose and wrap the electrode assembly, a plurality of convex parts are further arranged on the side, deviating from the electrode assembly, of the bottom surface film in the first direction, the convex parts are arranged at intervals, a gap between every two adjacent convex parts forms an exhaust channel, and the exhaust channels extend to the anti-explosion valve and communicate with the pressure relief hole; and the bottom supporting plate is arranged between the electrode assembly and the bottom surface film, and the bottom supporting plate is fixedly connected with the bottom surface film. Under the condition of thermal runaway, gas cannot be blocked by the bottom supporting plate after breaking through the insulating film, the gas flows to the anti-explosion valve through the exhaust channel and breaks through the anti-explosion valve under the pressure so as to be rapidly exhausted, the air pressure in the shell is prevented from being too large, and the explosion risk is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to new energy battery technical field especially relates to a battery monomer and battery package. BACKGROUND

[0002] Lithium ion battery will appear thermal runaway phenomenon when being impacted or internal short circuit during use, in order to improve the safety of lithium ion battery, the explosion-proof valve will be arranged on lithium ion battery, when the internal pressure of lithium ion battery increases due to thermal runaway, the explosion-proof valve will break to quickly reduce the internal pressure of lithium ion battery.

[0003] The conventional lithium ion battery includes a shell, a top cover, an insulating film, an electrode assembly and an explosion-proof valve, the electrode assembly is arranged in the shell, the top cover covers the shell, the insulating film wraps the electrode assembly to insulate and isolate the electrode assembly and the shell, and the explosion-proof valve is arranged on the top cover or the shell.

[0004] The conventional lithium ion battery includes a shell, a top cover, an insulating film, an electrode assembly and an explosion-proof valve, the electrode assembly is arranged in the shell, the top cover covers the shell, the insulating film wraps the electrode assembly to insulate and isolate the electrode assembly and the shell, and the explosion-proof valve is arranged on the top cover or the shell. SUMMARY

[0005] The utility model discloses a battery monomer to solve the problem that the gas of lithium ion battery in prior art cannot be discharged quickly when thermal runaway occurs, and further provides a battery package using the battery monomer.

[0006] In order to achieve the above-mentioned purpose, the utility model provides a battery monomer, the battery monomer has a first direction, and comprises:

[0007] The shell has a receiving cavity and a pressure relief hole communicating with the receiving cavity.

[0008] The electrode assembly is arranged in the receiving cavity.

[0009] The explosion-proof valve is fixedly connected with the shell and covers the pressure relief hole.

[0010] The insulation film comprises a bottom surface film and a side surface film connected with the bottom surface film, the bottom surface film and the side surface film enclose the electrode assembly, the bottom surface film is further provided with protrusions on the side away from the electrode assembly along the first direction, the protrusions are spaced apart, and the gap between two adjacent protrusions forms an exhaust passage, the exhaust passage extends to the explosion-proof valve and communicates with the pressure relief hole.

[0011] A bottom support plate is arranged between the electrode assembly and the bottom surface film, and the bottom support plate is fixedly connected with the bottom surface film.

[0012] In some embodiments, the bottom surface film is further provided with a plurality of first through holes, each of the first through holes penetrating the bottom surface film along the first direction, and the first through holes communicate with the exhaust passage.

[0013] In some embodiments, the bottom support plate is provided with a second through hole penetrating the bottom support plate along the first direction, the second through hole is staggered with the first through hole along a second direction, and the first direction and the second direction are perpendicular to each other.

[0014] In some embodiments, the bottom surface film is further provided with a first weak part, and the first weak part is arranged opposite to the explosion-proof valve along the first direction.

[0015] In some embodiments, the bottom surface film is provided with a notch, the notch communicates with part of the first through holes, the notch forms the first weak part, and the first direction and the second direction are perpendicular to each other.

[0016] In some embodiments, the bottom support plate is provided with a fourth weak part, and the fourth weak part is arranged opposite to the first weak part along the first direction.

[0017] In some embodiments, the bottom surface film is further provided with a second weak part, and the second weak part is arranged opposite to the first weak part along the second direction, and the second weak part is staggered with the explosion-proof valve along the second direction.

[0018] In some embodiments, the bottom support plate is further provided with a fifth weak part, the fifth weak part is arranged opposite to the fourth weak part along the second direction, and the fifth weak part is arranged opposite to the second weak part along the first direction.

[0019] In some embodiments, the side surface film is further provided with a third weak part.

[0020] The utility model further provides a battery pack, comprising the battery monomer of any one of the above technical schemes.

[0021] The utility model discloses a battery monomer and battery pack compared with prior art, its beneficial effect lies in: the bottom support plate is arranged between the electrode assembly and bottom surface film, and the bottom support plate can support the electrode assembly along the first direction, and the gas after breaking through the insulating film under the thermal runaway condition will not be blocked by the bottom support plate, and the interval between the convex part on the bottom surface film forms the exhaust passage, and the gas can flow to the explosion -proof valve through the exhaust passage, breaks through the explosion -proof valve under pressure to exhaust fast, avoids that the gas pressure in the shell is too big, reduces the explosion risk. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is the structural schematic diagram of the battery monomer of the utility model;

[0023] Figure 2 It is Figure 1 the structural schematic diagram of another view of the battery monomer of

[0024] Figure 3 It is Figure 1 the assembly structure schematic diagram of insulating film and bottom support plate of the battery monomer of

[0025] Figure 4 It is Figure 3 the exploded view schematic diagram of insulating film and bottom support plate of

[0026] Figure 5 It is Figure 4 the structural schematic diagram of insulating film of

[0027] Figure 6 It is Figure 4 the structural schematic diagram of bottom support plate of

[0028] In the drawing, 1, shell, 11, bottom plate, 12, side plate, 13, containing cavity, 14, pressure relief hole, 2, electrode assembly, 3, explosion -proof valve, 4, insulating film, 41, bottom surface film, 42, side surface film, 43, convex part, 44, exhaust passage, 45, first through -hole, 46, first weak part, 47, notch, 48, second weak part, 49, third weak part, 5, bottom support plate, 51, second through -hole, 52, fourth weak part, 53, fifth weak part, 6, cover plate, Z, first direction, Y, second direction. DETAILED DESCRIPTION

[0029] The specific implementation of the utility model is described in further detail below in combination with the drawings and examples. The following examples are used to illustrate the utility model, but not to limit the scope of the utility model.

[0030] The preferred embodiment of the battery monomer of the utility model is as follows: Figures 1 to 6As shown, the battery cell includes a shell 1, an electrode assembly 2, an explosion-proof valve 3, an insulation film 4, a bottom supporting plate 5 and a cover plate 6, and has a first direction Z, in this embodiment, the battery cell is a square battery, and the first direction Z is the height direction of the battery cell.

[0031] The shell 1 has a containing cavity 13 and a pressure relief hole 14 communicating with the containing cavity 13, and the electrode assembly 2, the insulation film 4 and the bottom supporting plate 5 are arranged in the containing cavity 13. In this embodiment, the shell 1 includes a bottom plate 11 and a side plate 12, the pressure relief hole 14 is arranged on the bottom plate 11, and the pressure relief hole 14 penetrates through the bottom plate 11 along the first direction Z. The explosion-proof valve 3 is fixedly connected with the bottom plate 11 and covers the pressure relief hole 14, and when the battery cell is in thermal runaway, the high-pressure gas in the containing cavity 13 can tear the explosion-proof valve 3 and quickly discharge from the pressure relief hole 14. The cover plate 6 is fixedly connected with the shell 1 and covers the containing cavity 13, so as to protect the electrode assembly 2, the insulation film 4 and the bottom supporting plate 5 in the containing cavity 13.

[0032] As shown in the figure, Figures 3 to 5 The insulation film 4 includes a bottom surface film 41 and a side surface film 42, the bottom surface film 41 is fixedly connected with the side surface film 42, and the bottom surface film 41 and the side surface film 42 enclose and cover the electrode assembly 2, so as to realize insulation and isolation between the shell 1 and the electrode assembly 2 and improve the insulation performance of the battery cell. In this embodiment, the bottom surface film 41 is oppositely arranged with the bottom plate 11 of the shell 1 along the first direction Z, the side surface film 42 has a plurality of side surface films, and the bottom surface film 41 and each side surface film 42 enclose to form a cuboid cavity with an open top, so as to accommodate the electrode assembly 2.

[0033] The bottom surface film 41 is further provided with a plurality of convex portions 43 away from the electrode assembly 2 along the first direction Z. After the battery cell is assembled, the convex portions 43 abut against the shell 1 under the action of gravity, so as to increase the gap between the insulation film 4 and the shell 1, and at this time, the gap between the adjacent two convex portions 43 forms an exhaust passage 44, which extends to the explosion-proof valve 3 and communicates with the pressure relief hole 14. When the battery cell is in thermal runaway, the high-pressure gas discharged from the insulation film 4 can quickly flow to the explosion-proof valve 3 through the exhaust passage 44 and be discharged through the explosion-proof valve 3.

[0034] In this embodiment, the convex portion 43 is semispherical, the inside of the convex portion 43 is a cavity, that is, the convex portion 43 is formed by the bottom surface film 41 being recessed towards the bottom plate 11 of the shell 1 along the first direction Z, and the convex portions 43 are uniformly distributed in an array on the bottom surface film 41. In other embodiments, the convex portion 43 can also be solid; the convex portion 43 can also be strip-shaped, and the convex portion 43 extends along the width direction of the battery cell.

[0035] As shown in the figure, Figures 1 to 4As shown, the bottom supporting plate 5 is arranged between the electrode assembly 2 and the bottom surface film 41, that is, the electrode assembly 2, the bottom supporting plate 5 and the bottom surface film 41 are arranged in sequence along the first direction Z. The bottom supporting plate 5 is fixedly connected with the bottom surface film 41, so that the bottom supporting plate 5 and the bottom surface film 41 can be pre-assembled as a whole. In this embodiment, the bottom supporting plate 5 is rectangular, and the bottom supporting plate 5 is fixedly bonded with the bottom surface film 41.

[0036] The bottom supporting plate 5 of the battery cell is arranged between the electrode assembly 2 and the bottom surface film 41. The bottom supporting plate 5 can support the electrode assembly 2 along the first direction Z, and the gas after breaking through the insulation film 4 in the thermal runaway condition will not be blocked by the bottom supporting plate 5. The interval between the convex portions 43 on the bottom surface film 41 forms an exhaust passage 44, and the gas can flow to the explosion-proof valve 3 through the exhaust passage 44, break through the explosion-proof valve 3 under pressure to quickly exhaust, avoid the internal gas pressure of the shell 1 being too large, and reduce the risk of explosion.

[0037] In some embodiments, the bottom surface film 41 is also provided with a plurality of first through holes 45, each first through hole 45 penetrating the bottom surface film 41 along the first direction Z. The first through holes 45 are in communication with the exhaust passage 44.

[0038] As shown in Figures 3 to 5 , the first through holes 45 are arranged on the bottom surface film 41 and can communicate the space inside the exhaust passage 44 and the insulation film 4 after penetrating the bottom surface film 41. When the battery cell is in thermal runaway, high-pressure gas can be quickly discharged to the exhaust passage 44 through the first through holes 45 for rapid pressure relief. In this embodiment, the first through holes 45 are circular holes, and a plurality of first through holes 45 are uniformly distributed in an array.

[0039] In some embodiments, the bottom supporting plate 5 is provided with a second through hole 51 penetrating the bottom supporting plate 5 along the first direction Z. The second through hole 51 is staggered with the first through hole 45 along the second direction Y, and the first direction Z and the second direction Y are perpendicular to each other.

[0040] As shown in Figure 3 , Figure 4 and Figure 6 , the second through hole 51 penetrating the bottom supporting plate 5 along the first direction Z is arranged on the bottom supporting plate 5. High-pressure gas can quickly pass through the bottom supporting plate 5 through the second through hole 51 to achieve rapid pressure relief. In this embodiment, the second through hole 51 is staggered with the first through hole 45 along the second direction Y. The second through hole 51 is a circular hole, and a plurality of second through holes 51 are uniformly distributed in an array. The second direction Y is the width direction of the battery cell.

[0041] The second through hole 51 and the first through hole 45 are staggered along the second direction Y, which can avoid the electrolyte after penetrating the second through hole 51 and the first through hole 45 from directly contacting the shell 1, prevent internal short circuit of the battery cell, and improve the safety of the battery cell.

[0042] In some embodiments, the bottom surface film 41 is further provided with a first weak portion 46, which is arranged opposite to the explosion-proof valve 3 along the first direction Z.

[0043] The first weak portion 46 is arranged on the bottom surface film 41 opposite to the explosion-proof valve 3, and forms a region of lower strength on the bottom surface film 41. When the first through hole 45 is insufficient to pass the thermal runaway gas, the bottom surface film 41 will tear at the position of the first weak portion 46 to form a larger pressure relief port to quickly discharge the high-pressure gas.

[0044] In some embodiments, the bottom surface film 41 is provided with a notch 47, which communicates with part of the first through hole 45, and forms the first weak portion 46.

[0045] The notch 47 forms the first weak portion 46, which can be directly cut to simplify the formation of the first weak portion 46. In other embodiments, the first weak portion 46 can also be a tooth hole or a cut slit that penetrates the bottom surface film 41.

[0046] The first weak portion 46 has a size in the thickness and width directions of the battery monomer that is smaller than the size in the thickness and width directions of the explosion-proof valve 3, so that the bottom surface film 41 is not blocked when it is torn. In this embodiment, the notch 47 is H-shaped, and in other embodiments, the notch 47 can also be one-shaped, X-shaped, etc.

[0047] The notch 47 communicates with part of the first through hole 45, and in the case that the high-pressure gas is not discharged in time through the first through hole 45, the notch 47 can be directly broken at the first through hole 45 and the bottom surface film 41 can be torn to form a pressure relief port.

[0048] In some embodiments, the bottom support plate 5 is provided with a fourth weak portion 52, which is arranged opposite to the first weak portion 46 along the first direction Z.

[0049] The fourth weak portion 52 is arranged on the bottom support plate 5 and forms a region of lower strength on the bottom support plate 5. When the second through hole 51 is insufficient to pass the thermal runaway gas, the bottom support plate 5 can tear at the position of the fourth weak portion 52 to form a larger pressure relief port to quickly discharge the high-pressure gas. The fourth weak portion 52 has a size in the thickness and width directions of the battery monomer that is smaller than the size in the thickness and width directions of the explosion-proof valve 3, so that the bottom support plate 5 is not blocked when it is torn.

[0050] In addition, since the fourth weak portion 52 is arranged opposite to the first weak portion 46 along the first direction Z, the gas passages formed by the tearing of the first weak portion 46 and the fourth weak portion 52 are opposite along the first direction Z, which facilitates the rapid discharge of the high-temperature and high-pressure gas to the explosion-proof valve 3 and improves the discharge efficiency of the gas.

[0051] In some embodiments, the bottom surface film 41 is further provided with a second weak portion 48, which is spaced apart from the first weak portion 46 along the second direction Y, and the second weak portion 48 is staggered with the explosion-proof valve 3 along the second direction Y.

[0052] The second weak portion 48 is provided on the bottom surface film 41 and is spaced apart from the first weak portion 46 along the second direction Y, and the second weak portion 48 is staggered with the explosion-proof valve 3. When the high-pressure gas generated by the thermal runaway of the battery cell tears the bottom surface film 41, the first weak portion 46 and the second weak portion 48 can be torn by the high-pressure gas respectively, multi-position gas exhaust is achieved, and rapid pressure relief is achieved. In the present embodiment, the second weak portion 48 has two, and the two second weak portions 48 are symmetrically arranged on both sides of the first weak portion 46. The gas can be evenly discharged, and the gas is not concentrated in a certain position for discharge.

[0053] In the present embodiment, the second weak portion 48 is formed by the notch 47, the notch 47 has two and is spaced apart, and the notch 47 extends along the second direction Y and connects part of the first through hole 45; in other embodiments, the second weak portion 48 can also be formed by a tooth hole or a cut seam.

[0054] In some embodiments, the bottom support plate 5 is further provided with a fifth weak portion 53, which is spaced apart from the fourth weak portion 52 along the second direction Y, and the fifth weak portion 53 is arranged opposite to the second weak portion 48 along the first direction Z.

[0055] The fifth weak portion 53 is provided on the bottom support plate 5 and is spaced apart from the fourth weak portion 52 along the second direction Y. When the high-pressure gas generated by the thermal runaway of the battery cell tears the bottom support plate 5, the fourth weak portion 52 and the fifth weak portion 53 can be torn by the high-pressure gas respectively, multi-position gas exhaust is achieved, and rapid pressure relief is achieved. In the present embodiment, the fifth weak portion 53 has two, and the two fifth weak portions 53 are symmetrically arranged on both sides of the fourth weak portion 52. The gas can be evenly discharged, and the gas is not concentrated in a certain position for discharge.

[0056] Since the fifth weak portion 53 is arranged opposite to the second weak portion 48 along the first direction Z, when the fifth weak portion 53 and the second weak portion 48 are torn by the high-temperature and high-pressure gas, the gas channels formed along the first direction Z are opposite, which facilitates the rapid discharge of the high-temperature and high-pressure gas to the explosion-proof valve 3, and improves the discharge efficiency of the gas.

[0057] In some embodiments, the side surface film 42 is further provided with a third weak portion 49.

[0058] A third weak portion 49 is arranged on the side film 42, and when a large amount of high-pressure gas is generated in the accommodation cavity 13 for a short time, the high-pressure gas can also tear the side film 42 from the third weak portion 49 to quickly release pressure. In this embodiment, the third weak portion 49 is two, and the two third weak portions 49 are symmetrically arranged at positions corresponding to the small faces of the battery monomer. The third weak portion 49 can be one of a notch, a tooth hole, and a cut seam.

[0059] The utility model further provides a preferred embodiment of battery pack, including battery monomer, the specific structure of battery monomer is same with the specific structure of battery monomer in any embodiment above, do not repeat here.

[0060] To sum up, the utility model embodiment provides a kind of battery monomer and battery pack, bottom support plate is arranged between electrode assembly and bottom film, bottom support plate can support electrode assembly along first direction, while gas is not blocked by bottom support plate after breaking through insulating film under thermal runaway condition, the interval between the convex part on bottom film forms exhaust passage, gas can flow to explosion-proof valve via exhaust passage, break through explosion-proof valve under pressure to quickly exhaust, avoid that the gas pressure in shell is too large, reduce explosion risk.

[0061] The above is only the preferred embodiment of the utility model, it should be pointed out, for the ordinary skilled person in the art, without departing from the technical principle of the utility model, can make several improvements and substitutions, these improvements and substitutions also should be regarded as the protection range of the utility model.

Claims

1. A battery cell, characterized by, The battery cell has a first direction, comprising: a housing having a receiving cavity and a pressure relief hole in communication with the receiving cavity; an electrode assembly disposed in the receiving cavity; an explosion-proof valve fixedly connected with the housing and covering the pressure relief hole; an insulation film including a bottom surface film and a side surface film connected with the bottom surface film, the bottom surface film and the side surface film enclosing the electrode assembly, the bottom surface film further being provided with protrusions on a side facing away from the electrode assembly along the first direction, the protrusions being spaced apart, and a gap between two adjacent protrusions forming an exhaust passage, the exhaust passage extending to the explosion-proof valve and being in communication with the pressure relief hole; a bottom support plate disposed between the electrode assembly and the bottom surface film, the bottom support plate being fixedly connected with the bottom surface film.

2. The battery cell of claim 1, wherein, The bottom surface film is further provided with a plurality of first through holes, each of the first through holes penetrating the bottom surface film along the first direction, the first through holes being in communication with the exhaust passage.

3. The battery cell of claim 2, wherein, The bottom support plate is provided with a second through hole penetrating the bottom support plate along the first direction, the second through hole being staggered with the first through holes along a second direction, the first direction and the second direction being perpendicular to each other.

4. The battery cell of claim 3, wherein, The bottom surface film is further provided with a first weak portion, the first weak portion being disposed opposite to the explosion-proof valve along the first direction.

5. The battery cell of claim 4, wherein, The bottom surface film is provided with a score line, the score line being in communication with part of the first through holes, and the score line forming the first weak portion.

6. The battery cell of claim 4, wherein, The bottom support plate is provided with a fourth weak portion, the fourth weak portion being disposed opposite to the first weak portion along the first direction.

7. The battery cell of claim 6, wherein, The bottom surface film is further provided with a second weak portion, the second weak portion being spaced apart from the first weak portion along the second direction, and the second weak portion being staggered with the explosion-proof valve along the second direction.

8. The battery cell of claim 7, wherein, The bottom support plate is further provided with a fifth weak portion, the fifth weak portion being spaced apart from the fourth weak portion along the second direction, and the fifth weak portion being disposed opposite to the second weak portion along the first direction.

9. The battery cell of any one of claims 1-8, wherein, The side surface film is further provided with a third weak portion.

10. A battery pack, characterized by, A battery cell as claimed in any one of claims 1-9.

Images