Single battery and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a single battery and a battery pack. The at least two flow guide convex ribs are convexly arranged on one side, back on to the top cover sheet, of the insulating part of the single battery, and are distributed at intervals along the periphery of the second liquid injection hole, so that the structural strength of the surrounding area of the second liquid injection hole can be improved by the flow guide convex ribs, and the risk of deformation of the insulating part is reduced. And moreover, a flow guide runner communicated with the second liquid injection hole is formed between every two adjacent flow guide convex ribs, so that the liquid injection efficiency can be ensured. Besides, in the radial direction of the second liquid injection hole, the flow guide convex ribs protrude towards the second liquid injection hole, and the included angle theta between the first straight line and the second straight line of each flow guide convex rib is larger than or equal to 10 degrees and smaller than or equal to 150 degrees, so that it can be guaranteed that the flow guide runner between every two adjacent flow guide convex ribs has the enough flow passing area, and the liquid injection efficiency is guaranteed; the risk that the first liquid injection hole and the second liquid injection hole are blocked is reduced, the manufacturing difficulty of the flow guide convex rib can be reduced, and the manufacturing cost of the single battery is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a single battery and a battery pack. BACKGROUND

[0002] A power battery generally comprises an electrode assembly, a metal shell for accommodating the electrode assembly, and a battery top cover. The battery top cover is provided with a liquid injection hole for injecting electrolyte, i.e., the electrolyte is injected into the power battery through the liquid injection hole. The lower plastic of the power battery is provided with a through hole in communication with the liquid injection hole, and the electrolyte is injected through the through hole on the lower plastic. However, the structural strength of the area around the through hole on the lower plastic is low and is prone to deformation. CONTENT OF THE UTILITY MODEL

[0003] The present application provides a single battery and a battery pack, which can improve the structural strength of the insulating member, ensure the liquid injection efficiency, and reduce the manufacturing difficulty of the flow guide ribs.

[0004] The present application provides a single battery. The single battery comprises a shell, and the shell has a receiving cavity. The single battery comprises an electrode assembly, and the electrode assembly is arranged in the receiving cavity. The single battery comprises a top cover sheet, and the top cover sheet is connected to one side of the shell and covers and seals the receiving cavity. The top cover sheet is provided with a first liquid injection hole. The single battery comprises an insulating member, and the insulating member is connected to one side of the top cover sheet close to the electrode assembly. The insulating member is provided with a second liquid injection hole in communication with the first liquid injection hole. The single battery comprises at least two flow guide ribs, each flow guide rib is protruded from one side of the insulating member away from the top cover sheet, and each flow guide rib is distributed along the outer periphery of the second liquid injection hole, so that a flow guide flow channel in communication with the second liquid injection hole is formed between two adjacent flow guide ribs. In the radial direction of the second liquid injection hole, the flow guide rib protrudes towards the second liquid injection hole, and the flow guide rib has an inner wall surface close to the second liquid injection hole. The single battery has a height direction and a reference plane perpendicular to the height direction. In the extension direction of the flow guide rib, the flow guide rib comprises a first end point and a second end point. In the height direction, the normal projection of the inner wall surface on the reference plane is a circular arc. The connecting line between the normal projection of the first end point on the reference plane and the center of the circular arc forms a first straight line, and the connecting line between the normal projection of the second end point on the reference plane and the center of the circular arc forms a second straight line. The included angle between the first straight line and the second straight line is θ, and satisfies: 10°≤θ≤150°.

[0005] In an embodiment of the present application, the included angle θ between the first straight line and the second straight line satisfies: 30°≤θ≤60°.

[0006] In an embodiment of the present application, in the radial direction of the second liquid injection hole, the flow guide rib is arranged away from the second liquid injection hole.

[0007] In an embodiment of the present application, the diameter of the second liquid injection hole is D mm, and the minimum distance between the flow guide rib and the second liquid injection hole is a mm, satisfying: 0.01 < a / D < 0.67, or 0.1 < a / D < 0.45.

[0008] In an embodiment of the present application, the minimum distance between the flow guide rib and the second liquid injection hole is a mm, satisfying: 0.2 < a < 2; or the diameter of the second liquid injection hole is D mm, satisfying: 3 < D < 18.

[0009] In an embodiment of the present application, the top cover assembly has a length direction; the insulating member is provided with an explosion-proof valve boss, and the explosion-proof valve boss and the at least two flow guide ribs are spaced apart along the length direction; wherein the size of the top cover sheet in the length direction is L mm, and the minimum distance between the flow guide rib and the explosion-proof valve boss in the length direction is L1 mm, satisfying: 0.005 < L1 / L < 1, or 0.005 < L1 / L < 0.91.

[0010] In an embodiment of the present application, the top cover assembly has a length direction; the insulating member is provided with an explosion-proof valve boss, and the explosion-proof valve boss and the at least two flow guide ribs are spaced apart along the length direction; wherein the minimum distance between the flow guide rib and the explosion-proof valve boss in the length direction is L1 mm, satisfying: 3 < L1 < 500; or the size of the top cover sheet in the length direction is L mm, satisfying: 10 < L < 600.

[0011] In an embodiment of the present application, the top cover assembly has a length direction; the top cover assembly further comprises a pole, and the pole is arranged between the top cover sheet and the insulating member, and the pole and the at least two flow guide ribs are spaced apart along the length direction; wherein the size of the top cover sheet in the length direction is L mm, and the minimum distance between the flow guide rib and the pole for connecting the end portions of the electrode assembly in the length direction is L2 mm, satisfying: 0.006 < L2 / L < 1, or 0.006 < L2 / L < 0.83.

[0012] In an embodiment of the present application, the top cover assembly has a length direction; the top cover assembly further comprises a pole, and the pole is arranged between the top cover sheet and the insulating member, and the pole and the at least two flow guide ribs are spaced apart along the length direction; wherein the minimum distance between the flow guide rib and the pole for connecting the end portions of the electrode assembly in the length direction is L2 mm, satisfying: 4 < L2 < 500; or the size of the top cover sheet in the length direction is L mm, satisfying: 10 < L < 600.

[0013] In an embodiment of the present application, the side of the flow guide rib facing the second liquid injection hole is provided with a through hole and / or a blind hole.

[0014] Correspondingly, the present application also provides a battery pack comprising a box body and a single battery as described in the above embodiments, and the single battery is arranged in the box body.

[0015] The application has the advantages that, different from the prior art, the application provides a single battery and a battery pack. The insulating piece of the single battery is provided with at least two flow guide ribs on the side away from the top cover sheet, and the flow guide ribs are distributed along the outer periphery of the second liquid injection hole. The flow guide ribs can improve the structural strength of the area around the second liquid injection hole and reduce the risk of deformation of the insulating piece. In addition, a flow guide flow channel is formed between the two adjacent flow guide ribs and communicates with the second liquid injection hole. The flow guide flow channel can guide the electrolyte during injection of the electrolyte from the second liquid injection hole, thereby facilitating the guarantee of the injection efficiency. Furthermore, in the radial direction of the second liquid injection hole, the flow guide ribs protrude towards the second liquid injection hole, and the included angle θ between the first straight line and the second straight line of the flow guide ribs satisfies 10°≤θ≤150°. This not only ensures that the flow guide flow channel between the two adjacent flow guide ribs has sufficient flow area and guides the injection of the electrolyte, thereby facilitating the guarantee of the injection efficiency and reducing the risk of blockage of the first liquid injection hole and the second liquid injection hole, but also reduces the manufacturing difficulty of the flow guide ribs and facilitates the reduction of the manufacturing cost of the single battery. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort.

[0017] Figure 1 is a structural schematic diagram of an embodiment of the single battery of the application;

[0018] Figure 2 is Figure 1 an exploded structural schematic diagram of the single battery shown in FIG. 1;

[0019] Figure 3 is a structural schematic diagram of an embodiment of the top cover assembly of the application;

[0020] Figure 4 is Figure 3 a structural schematic diagram of another view of the top cover assembly shown in FIG. 5;

[0021] Figure 5 is Figure 3 a bottom structural schematic diagram of the top cover assembly shown in FIG. 5;

[0022] Figure 6 is Figure 5 a structural schematic diagram of region A of the top cover assembly shown in FIG. 5;

[0023] Figure 7is a structural schematic view of a first end point of a guide convex rib in the reference plane of an embodiment of the application in a normal projection;

[0024] Figure 8 is a structural schematic view of a second end point of a guide convex rib in the reference plane of an embodiment of the application in a normal projection.

[0025] Legend of reference signs:

[0026] 10 single battery; 11 shell; 111 accommodating cavity; 12 electrode assembly; 20 top cover assembly; 21 top cover sheet; 211 first liquid injection hole; 22 insulating piece; 221 second liquid injection hole; 222 anti-explosion valve boss; 23 guide convex rib; 23a first end point; 23b second end point; 231 guide flow channel; 24 pole; 232 inner wall surface. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative work are within the protection scope of the application. In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the application, and are not used to limit the application. In the application, unless otherwise specified and limited, the terms such as "upper", "lower", "left", "right" refer to the upper, lower, left and right of the device in the actual use or working state, and the specific direction is the direction of the drawing surface in the drawings.

[0028] In the application, unless otherwise explicitly specified and limited, the terms such as "connected", "connected", "stacked" and the like should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal connection of two elements or the interaction relationship between two elements. For a person of ordinary skill in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0029] The application provides a single battery and a battery pack, which are described in detail below. It should be noted that the description order of the following embodiments is not limited as the preferred order of the embodiments of the application. In the following embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0030] To solve the technical problem of low structural strength and easy deformation of the existing technology, an embodiment of the present application provides a single battery. The single battery includes a shell having a receiving cavity. The single battery includes an electrode assembly disposed in the receiving cavity. The single battery includes a top cover sheet connected to one side of the shell and covering the receiving cavity, and the top cover sheet is provided with a first liquid injection hole. The single battery includes an insulating piece connected to one side of the top cover sheet close to the electrode assembly, and the insulating piece is provided with a second liquid injection hole in communication with the first liquid injection hole. The single battery includes at least two flow guide ribs, each flow guide rib protruding from one side of the insulating piece away from the top cover sheet, and each flow guide rib is spaced apart along the outer periphery of the second liquid injection hole, so that two adjacent flow guide ribs form a flow guide channel in communication with the second liquid injection hole. Wherein, in the radial direction of the second liquid injection hole, the flow guide rib protrudes towards the second liquid injection hole, and the flow guide rib has an inner wall surface close to the second liquid injection hole; the single battery has a height direction and a reference plane perpendicular to the height direction, along the extension direction of the flow guide rib, the flow guide rib includes a first end point and a second end point; along the height direction, the normal projection of the inner wall surface on the reference plane is a circular arc, the normal projection of the first end point on the reference plane and the center line of the circular arc form a first straight line, the normal projection of the second end point on the reference plane and the center line of the circular arc form a second straight line, the included angle between the first straight line and the second straight line is θ, and satisfies: 10°≤θ≤150°. Details are described below.

[0031] Please refer to Figure 1 , Figure 1 is a structural schematic diagram of an embodiment of the single battery of the present application.

[0032] In an embodiment, the battery pack includes a box and a plurality of single batteries 10, and the plurality of single batteries 10 are accommodated in the box. The single battery 10 includes but is not limited to a lithium ion secondary battery, a lithium ion primary battery, a lithium-sulfur battery, a sodium lithium ion battery, a sodium ion battery or a magnesium ion battery, etc., and the present disclosure does not limit this. The battery pack is a power supply for an electric device. The electric device can be a mobile phone, a portable device, a notebook computer, an electric vehicle, an electric vehicle, a ship, a spacecraft, an electric toy and an electric tool, etc. For example, the spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc.; the electric toy includes a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy and an electric plane toy, etc.; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool and a railway electric tool, such as a power drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator and an electric planer, etc.

[0033] The single battery 10 of the embodiment of the present application is described below.

[0034] Please refer to Figures 2 to 5 ,Figure 2 is Figure 1 is an exploded structural schematic view of the monomer battery shown in Figure 3 is a structural schematic view of an embodiment of a top cover assembly of the present application, Figure 4 is Figure 3 is a bottom structural schematic view of the top cover assembly shown in Figure 5 is Figure 3 is a structural schematic view of the top cover assembly from another perspective shown in

[0035] In an embodiment, the monomer battery 10 comprises a shell 11 having a receiving cavity 111. The monomer battery 10 further comprises an electrode assembly 12 disposed in the receiving cavity 111. The electrode assembly 12 is stacked and / or wound by a positive electrode sheet, a negative electrode sheet and a separator. The monomer battery 10 further comprises a top cover assembly 20 connected to one side of the shell 11 and covering the receiving cavity 111.

[0036] The top cover assembly 20 comprises a top cover sheet 21 connected to one side of the shell 11 and covering the receiving cavity 111. The top cover assembly 20 further comprises an insulating piece 22 connected to one side of the top cover sheet 21 close to the electrode assembly 12. The top cover sheet 21 is provided with a first liquid injection hole 211, and the insulating piece 22 is provided with a second liquid injection hole 221 in communication with the first liquid injection hole 211. The electrolyte is injected into the receiving cavity 111 through the first liquid injection hole 211 and the second liquid injection hole 221 in sequence.

[0037] The top cover assembly 20 further comprises at least two flow guide ribs 23. Each flow guide rib 23 is protruded from one side of the insulating piece 22 away from the top cover sheet 21, and each flow guide rib 23 is spacedly distributed along the outer periphery of the second liquid injection hole 221, so that a flow guide flow channel 231 in communication with the second liquid injection hole 221 is formed between two adjacent flow guide ribs 23.

[0038] In the above manner, the one side of the insulating piece 22 of the monomer battery 10 of the present embodiment is protruded with at least two flow guide ribs 23 away from the top cover sheet 21, and each flow guide rib 23 is spacedly distributed along the outer periphery of the second liquid injection hole 221. The flow guide rib 23 can improve the structural strength of the area around the second liquid injection hole 221 and reduce the risk of deformation of the insulating piece 22. Moreover, the flow guide flow channel 231 in communication with the second liquid injection hole 221 is formed between two adjacent flow guide ribs 23, and the flow guide flow channel 231 can guide the electrolyte during the injection of the electrolyte from the second liquid injection hole 221, thus being conducive to ensuring the injection efficiency.

[0039] Please refer to Figures 6 to 8 , Figure 6 is Figure 5 is a structural schematic view of the top cover assembly A area shown in Figure 7 is a structural schematic view of an embodiment of the normal projection of the first end point of the flow guide rib on the reference plane,Figure 8 is a structural schematic view of an embodiment of the application. The second end point of the flow guide rib is the normal projection of the second end point of the flow guide rib on the reference plane.

[0040] In an embodiment, the flow guide rib 23 is spaced apart from the second liquid injection hole 221 in the radial direction of the second liquid injection hole 221. In the radial direction of the second liquid injection hole 221, the flow guide rib 23 protrudes towards the second liquid injection hole 221. Figure 6 Exemplarily, the flow guide rib 23 is shown protruding towards the second liquid injection hole 221.

[0041] In the above manner, in the radial direction of the second liquid injection hole 221, the flow guide rib 23 is spaced apart from the second liquid injection hole 221, which means that the opening area of the second liquid injection hole 221 is small, and the top cover sheet 21 exposed by the second liquid injection hole 221 is small, so as to reduce the risk of contact between the electrode assembly 12 and the top cover sheet 21, i.e. to reduce the risk of short circuit between the electrode assembly 12 and the top cover sheet 21.

[0042] It should be noted that the single battery 10 has a height direction Z, the top cover assembly 20 is covered on one side of the shell 11 along the height direction Z, and the top cover sheet 21 and the insulating piece 22 are stacked along the height direction Z. The radial direction of the second liquid injection hole 221 is perpendicular to the height direction Z.

[0043] Of course, in other embodiments of the application, the flow guide rib 23 can also border the second liquid injection hole 221 in the radial direction of the second liquid injection hole 221, which is not limited herein.

[0044] In an embodiment, the single battery 10 also has a reference plane O perpendicular to the height direction Z. Along the extension direction of the flow guide rib 23, the flow guide rib 23 includes a first end point 23a and a second end point 23b. Specifically, the first end point 23a and the second end point 23b are respectively the outermost positions of the flow guide rib 23 in the extension direction thereof, and the distances between the first end point 23a and the second end point 23b and the midpoint of the flow guide rib 23 are both greater than the distances between other positions of the flow guide rib 23 and the midpoint. In the radial direction of the second liquid injection hole 221, the flow guide rib 23 has an inner wall surface 232 close to the second liquid injection hole 221. In the height direction Z, the normal projection of the inner wall surface 232 on the reference plane O is a circular arc, the first straight line M is formed by the normal projection of the first end point 23a on the reference plane O and the line connecting the center Q of the circular arc and the reference plane O, and the second straight line N is formed by the normal projection of the second end point 23b on the reference plane O and the line connecting the center Q of the circular arc and the reference plane O. It can be understood that the reference plane O can be the surface of the top cover sheet 21 facing the insulating piece 22, etc.

[0045] As Figure 6As shown, the included angle between the first straight line M and the second straight line N is θ, which satisfies: 10°≤θ≤150°, for example, it can be any value in 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 90°, 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, 135°, 140°, 145°, 150°, etc. By reasonably setting the included angle θ between the first straight line M and the second straight line N, on the one hand, the flow guide flow channel 231 between the two adjacent flow guide ribs 23 can have sufficient flow area, and the flow guide flow channel 231 guides the electrolyte injection, thereby being conducive to ensuring the injection efficiency and reducing the risk of plugging of the first injection hole 211 and the second injection hole 221, on the other hand, the manufacturing difficulty of the flow guide rib 23 can be reduced, and the manufacturing cost of the single battery 10 can be reduced.

[0046] Further, the included angle θ between the first straight line M and the second straight line N satisfies 30°≤θ≤60°. In this way, the present embodiment can maximize the flow area of the flow guide flow channel 231 between the two adjacent flow guide ribs 23, and the flow guide flow channel 231 guides the electrolyte injection, thereby being conducive to ensuring the injection efficiency and reducing the risk of plugging of the first injection hole 211 and the second injection hole 221; and the present embodiment can maximize the manufacturing difficulty of the flow guide rib 23, and the manufacturing cost of the single battery 10 can be reduced.

[0047] In an embodiment, the diameter of the second injection hole 221 is D mm, and the minimum distance between the flow guide rib 23 and the second injection hole 221 is a mm, which satisfies: 0.01<a / D≤0.67, for example, it can be any value in 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, etc.

[0048] By the above manner, the minimum distance between the flow guide protruding ribs 23 and the second liquid injection holes 221 is reasonably set, on the one hand, to ensure that the flow guide protruding ribs 23 can improve the structural strength of the area around the second liquid injection holes 221, reduce the risk of deformation of the insulating part 22, and on the other hand, to minimize the opening area of the second liquid injection holes 221, so that the top cover sheet 21 exposed by the second liquid injection holes 221 is less, which can reduce the risk of short circuit caused by the contact between the electrode assembly 12 and the top cover sheet 21.

[0049] Further, the minimum distance a mm between the flow guide protruding ribs 23 and the second liquid injection holes 221 satisfies: 0.1 < a / D < 0.45. In this way, the present embodiment can maximize the guarantee that the flow guide protruding ribs 23 can improve the structural strength of the area around the second liquid injection holes 221, reduce the risk of deformation of the insulating part 22, and minimize the opening area of the second liquid injection holes 221, so that the top cover sheet 21 exposed by the second liquid injection holes 221 is less, which can reduce the risk of short circuit caused by the contact between the electrode assembly 12 and the top cover sheet 21.

[0050] Optionally, the diameter D mm of the second liquid injection hole 221 satisfies 3≤D≤18, for example, can be any value in 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9.0, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10.0, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 11.0, 11.1, 11.2, 11.3, 11.4, 11.5, 11.6, 11.7, 11.8, 11.9, 12.0, 12.1, 12.2, 12.3, 12.4, 12.5, 12.6, 12.7, 12.8, 12.9, 13.0, 13.1, 13.2, 13.3, 13.4, 13.5, 13.6, 13.7, 13.8, 13.9, 14.0, 14.1, 14.2, 14.3, 14.4, 14.5, 14.6, 14.7, 14.8, 14.9, 15.0, 15.1, 15.2, 15.3, 15.4, 15.5, 15.6, 15.7, 15.8, 15.9, 16.0, 16.1, 16.2, 16.3, 16.4, 16.5, 16.6, 16.7, 16.8, 16.9, 17.0, 17.1, 17.2, 17.3, 17.4, 17.5, 17.6, 17.7, 17.8, 17.9, 18.0.

[0051] In an embodiment, the minimum distance a mm between the flow guide rib 23 and the second liquid injection hole 221 satisfies: 0.2≤a≤2, for example, can be any value in 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0.

[0052] In this way, by reasonably setting the minimum distance between the flow guide ribs 23 and the second liquid injection hole 221, on the one hand, the flow guide ribs 23 can improve the structural strength of the area around the second liquid injection hole 221, reducing the risk of deformation of the insulating part 22, and on the other hand, the opening area of the second liquid injection hole 221 is as small as possible, so that the second liquid injection hole 221 exposes less of the top cover sheet 21, which can reduce the risk of short circuiting caused by contact between the electrode assembly 12 and the top cover sheet 21.

[0053] In an embodiment, the insulating part 22 is provided with an explosion-proof valve boss 222. The explosion-proof valve boss 222 is arranged opposite the explosion-proof valve on the top cover sheet 21. The explosion-proof valve boss 222 is provided with a plurality of through holes. When the explosion-proof valve is opened, the high-temperature and high-pressure gas inside the single battery 10 is discharged from the explosion-proof valve through the through holes on the explosion-proof valve boss 222.

[0054] The single battery 10 has a length direction X perpendicular to the height direction Z. The explosion-proof valve boss 222 and the at least two flow guide ribs 23 described above are spaced apart along the length direction X. The size of the top cover sheet 21 in the length direction X is L mm, and the minimum distance between the flow guide ribs 23 and the explosion-proof valve boss 222 in the length direction X is L1 mm, which satisfies: 0.005≤L1 / L<1, for example, it can be any value in 0.005, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, etc.

[0055] By the above manner, the present embodiment sets the minimum distance between the flow guide protrusions 23 and the explosion-proof valve boss 222 reasonably, so as to avoid the minimum distance between the flow guide protrusions 23 and the explosion-proof valve boss 222 being too small to affect the explosion pressure of the explosion-proof valve. If the minimum distance between the flow guide protrusions 23 and the explosion-proof valve boss 222 is too small, the electrolyte injected from the second liquid injection hole 221 is easy to enter the explosion-proof valve boss 222, so as to cause the actual explosion pressure of the explosion-proof valve to be less than the design value.

[0056] In an embodiment, the minimum distance L1 mm of the flow guide protrusions 23 and the explosion-proof valve boss 222 in the length direction X satisfies 3≤L1≤500, for example, can be any value in 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, etc.

[0057] By the above manner, the present embodiment sets the minimum distance between the flow guide protrusions 23 and the explosion-proof valve boss 222 reasonably, so as to avoid the minimum distance between the flow guide protrusions 23 and the explosion-proof valve boss 222 being too small to affect the explosion pressure of the explosion-proof valve. If the minimum distance between the flow guide protrusions 23 and the explosion-proof valve boss 222 is too small, the electrolyte injected from the second liquid injection hole 221 is easy to enter the explosion-proof valve boss 222, so as to cause the actual explosion pressure of the explosion-proof valve to be less than the design value.

[0058] Optionally, the size L mm of the top cover sheet 21 in the length direction X also satisfies 10≤L≤600, for example, can be any value in 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, etc.

[0059] In an embodiment, the single battery cell 10 further comprises a pole post 24 disposed between the top cover sheet 21 and the insulating member 22, the pole post 24 being spaced apart from the at least two flow guide ribs 23 along the length direction X. The length of the top cover sheet 21 along the length direction X is L mm, the minimum distance between the end portions of the pole post 24 and the flow guide ribs 23 along the length direction X is L2 mm, and the following condition is satisfied: 0.006 < L2 / L < 1, for example, 0.0067, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, etc.

[0060] In the above manner, by reasonably setting the minimum distance between the flow guide ribs 23 and the pole post 24, the structural strength of the top cover sheet 21 between the first injection hole 211 and the pole post 24 can be ensured. If the minimum distance between the flow guide ribs 23 and the pole post 24 is too small, it means that the distance between the first injection hole 211 and the pole post 24 is too small, which will result in the structural strength of the top cover sheet 21 between the first injection hole 211 and the pole post 24 being too small, and deformation and other problems are likely to occur.

[0061] In an embodiment, the minimum distance L2 between the flow guide ribs 23 and the pole 24 in the length direction X at the end of the electrode assembly 12 satisfies: 4≤L2≤500, for example, can be any value in 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, etc.

[0062] In the above manner, the present embodiment is advantageous in ensuring the structural strength of the top cover sheet 21 between the first injection hole 211 and the pole 24 by reasonably setting the minimum distance between the flow guide ribs 23 and the pole 24. If the minimum distance between the flow guide ribs 23 and the pole 24 is too small, it means that the distance between the first injection hole 211 and the pole 24 is too small, which will result in too small structural strength of the top cover sheet 21 between the first injection hole 211 and the pole 24, and prone to deformation and other problems.

[0063] In an embodiment, the side of the flow guide rib 23 facing the second injection hole 221 is provided with a through hole and / or a blind hole. The through hole and the second injection hole 221 are in communication, and the blind hole is also in communication with the second injection hole 221. In this way, the electrolyte injected from the second injection hole 221 can buffer when impacting the flow guide rib 23, which is advantageous in improving the injection efficiency. The flow guide rib 23 can be provided with one or more through holes, and the plurality of through holes are distributed along the extension direction of the flow guide rib 23; or the flow guide rib 23 can be provided with one or more blind holes, and the plurality of blind holes are distributed along the extension direction of the flow guide rib 23; or the flow guide rib 23 is provided with both through holes and blind holes, which is not limited herein. In an embodiment, the through hole and / or the blind hole are provided on the inner wall surface 232 close to the second injection hole 221.

[0064] The performance of the technical solutions provided by the embodiments of the present application is evaluated below.

[0065] Examples 1 to 11 are provided. Examples 1 to 9 satisfy 10°≤θ≤150°, and examples 10 and 11 do not satisfy 10°≤θ≤150°. The specific parameters and test results are shown in the table below.

[0066] Table 1

[0067]

[0068]

[0069] Note that the angle θ can be measured directly using a measuring tool, or an image of the flow guide rib 23 can be acquired using a camera element such as a CCD (charge coupled device) camera, and then the angle θ can be measured on the image using a measuring tool, without limitation.

[0070] The injection efficiency can be measured by measuring the injection efficiency of the lithium ion battery prepared in the above examples, using the insulating member in the present application for the insulating member in the lithium ion battery, and placing the lithium ion battery in an injection machine. The injection machine first evacuates the inside of the lithium ion battery, so that the air pressure inside the lithium ion battery is below -90 Kpa. At this time, the electrolyte is already stored in the injection cup. Since the inside of the lithium ion battery is in a negative pressure state, the electrolyte flows into the inside of the lithium ion battery. Then, the injection machine performs positive and negative pressure alternating circulation (positive pressure 180 Kpa (30-60 S) and negative pressure -60 Kpa (3-15 S), 4-12 cycles) to the lithium ion battery, so that the electrolyte can be fully injected into the inside of the lithium ion battery. The time required for the overall injection process is recorded as Tmin. The insulating member in the lithium ion battery is replaced with a conventional insulating member (i.e., no structure is provided at the through hole of the insulating member), and the same injection operation is performed on the lithium ion battery. The time required for the overall injection process is recorded as tmin, and the injection efficiency is t / T x 100%.

[0071] It can be seen that the above examples 1 to 11 have high injection efficiency. In particular, examples 1 to 9 not only ensure that the flow guide flow channel 231 between the two adjacent flow guide ribs 23 has sufficient flow area, but also guide the electrolyte to be injected, thereby facilitating the guarantee of injection efficiency and reducing the risk of blockage of the first injection hole 211 and the second injection hole 221. In addition, the manufacturing difficulty of the flow guide rib 23 is reduced, which is conducive to reducing the manufacturing cost of the single battery 10. Although example 10 has high injection efficiency, the angle θ of the flow guide rib 23 in example 10 is small, which results in high manufacturing difficulty. The angle θ of the flow guide rib 23 in example 11 is large, and the injection efficiency of example 11 is lower than that of examples 1 to 9.

[0072] Examples 12 to 23 are provided. Examples 12 to 21 satisfy 0.01 < a / D ≤ 0.67, and examples 22 and 23 do not satisfy 0.01 < a / D ≤ 0.67. The specific parameters and test results are shown in the following table.

[0073] Table 2

[0074]

[0075] It should be noted that the diameter of the second liquid injection hole 221 and the minimum distance between the flow guide protrusions 23 and the second liquid injection hole 221 can be measured directly using a measuring tool or by using a camera element such as a CCD (charge coupled device) camera to obtain an image of the flow guide protrusions 23 and the second liquid injection hole 221, and then measuring on the image using a measuring tool, which is not limited herein.

[0076] The flatness of the insulation member 22 in the above table is the flatness of the insulation member 22 around the second liquid injection hole 221, which represents the structural strength of the area around the second liquid injection hole 221. The smaller the flatness of the insulation member 22 around the second liquid injection hole 221, the higher the structural strength of the area around the second liquid injection hole 221. The larger the flatness of the insulation member 22 around the second liquid injection hole 221, the lower the structural strength of the area around the second liquid injection hole 221. The flatness of the insulation member 22 can be measured by measuring the flatness of the lithium ion battery prepared in the above examples, disassembling the prepared lithium ion battery after a period of time, placing the insulation member 22 obtained by disassembly on a platform, placing the base of the height gauge on the platform, adjusting the sliding rod of the height gauge to make it contact the surface of the insulation member 22 around the second liquid injection hole 221, moving the height gauge, recording the readings of multiple points, and calculating the flatness of the insulation member 22 by calculating the difference between the maximum and minimum readings.

[0077] It can be seen that the insulation member 22 in examples 12 to 23 above has a small flatness. In particular, the insulation member 22 in examples 12 to 21 has a relatively smaller flatness, which on the one hand ensures that the flow guide protrusions 23 can improve the structural strength of the area around the second liquid injection hole 221 and reduce the risk of deformation of the insulation member 22, and on the other hand reduces the opening area of the second liquid injection hole 221 as much as possible, so that the second liquid injection hole 221 exposes less of the top cover sheet 21, thereby reducing the risk of short circuit caused by contact between the electrode assembly 12 and the top cover sheet 21. Although the insulation member 22 in example 22 has a small flatness, the minimum distance between the flow guide protrusions 23 and the second liquid injection hole 221 in the insulation member 22 in example 22 is small, resulting in a high manufacturing difficulty. The minimum distance between the flow guide protrusions 23 and the second liquid injection hole 221 in the insulation member 22 in example 23 is large, and the flatness of the insulation member 22 in example 23 is larger than that in examples 12 to 21, which means that the structural strength of the area around the second liquid injection hole 221 in example 23 is lower.

[0078] Examples 24 to 36 are provided. Examples 24 to 35 satisfy 0.005≤L1 / L<1, and example 36 does not satisfy 0.005≤L1 / L<1. The specific parameters and test results are shown in the table below.

[0079] Table 3

[0080]

[0081] It should be noted that the measurement of the dimension of the top cover sheet 21 in the length direction X and the minimum distance between the flow guide rib 23 and the relief valve boss 222 in the length direction X can be directly measured by using a measuring tool, or an image of the top cover sheet 21, the flow guide rib 23 and the relief valve boss 222 is obtained by using a camera element such as a CCD (charge coupled device) camera, and then the measurement is performed on the image by using a measuring tool, which is not limited herein.

[0082] The measurement of the relief valve ignition pressure can be that a hose is inserted into the first liquid injection hole 211 of the single battery 10, and the first liquid injection hole 211 is sealed by using a sealant, and the inside of the single battery 10 is inflated (for example, an inert gas such as helium). The hose is connected with a barometer, and the inside pressure of the single battery 10 is displayed by the barometer. The inside pressure of the single battery 10 displayed by the barometer when the relief valve is ignited is read, and the actual ignition pressure of the relief valve is obtained.

[0083] It can be seen that the above examples 24 to 36 all have good relief valve ignition pressure. In particular, the above examples 24 to 35 can reasonably set the minimum distance between the flow guide rib 23 and the relief valve boss 222, and avoid the minimum distance between the flow guide rib 23 and the relief valve boss 222 being too small to affect the ignition pressure of the relief valve as much as possible. Compared with examples 24 to 35, the minimum distance between the flow guide rib 23 and the relief valve boss 222 in example 36 is smaller, resulting in that the actual ignition pressure of the relief valve is smaller.

[0084] Examples 37 to 50 are provided. Examples 37 to 49 satisfy 0.006 < L2 / L < 1, and example 50 does not satisfy 0.006 < L2 / L < 1. The specific parameters and test results are shown in the following table.

[0085] Table 4

[0086]

[0087]

[0088] It should be noted that the measurement of the minimum distance L2 mm between the flow guide rib 23 and the pole 24 can be directly measured by using a measuring tool, or an image of the flow guide rib 23 and the pole 24 is obtained by using a camera element such as a CCD (charge coupled device) camera, and then the measurement is performed on the image by using a measuring tool, which is not limited herein.

[0089] The planeness of the top cover sheet 21 between the first liquid injection hole 211 and the pole 24 represents the structural strength of the top cover sheet 21 between the first liquid injection hole 211 and the pole 24. The smaller the planeness of the top cover sheet 21 between the first liquid injection hole 211 and the pole 24, the higher the structural strength of the top cover sheet 21 between the first liquid injection hole 211 and the pole 24. The larger the planeness of the top cover sheet 21 between the first liquid injection hole 211 and the pole 24, the lower the structural strength of the top cover sheet 21 between the first liquid injection hole 211 and the pole 24. The planeness of the top cover sheet 21 between the first liquid injection hole 211 and the pole 24 can be measured by: measuring the planeness of the lithium ion battery prepared in the above example, disassembling the prepared lithium ion battery after a period of time, placing the disassembled top cover sheet 21 on a platform, placing the base of the height gauge on the platform, adjusting the sliding rod of the height gauge to make it contact the surface of the top cover sheet 21 between the first liquid injection hole 211 and the pole 24, moving the height gauge, recording the readings of multiple points, and calculating the planeness of the top cover sheet 21 between the first liquid injection hole 211 and the pole 24 by calculating the difference between the maximum and minimum readings.

[0090] It can be seen that the top cover sheet 21 between the first liquid injection hole 211 and the pole 24 in examples 37 to 50 has a small planeness. In particular, the top cover sheet 21 between the first liquid injection hole 211 and the pole 24 in examples 37 to 49 has a smaller planeness, and by reasonably setting the minimum distance between the flow guide protruding ribs 23 and the pole 24, the structural strength of the top cover sheet 21 between the first liquid injection hole 211 and the pole 24 is ensured. Compared with examples 37 to 49, the minimum distance between the flow guide protruding ribs 23 and the pole 24 in example 50 is smaller, the top cover sheet 21 between the first liquid injection hole 211 and the pole 24 has a larger planeness, which means that the structural strength of the top cover sheet 21 between the first liquid injection hole 211 and the pole 24 is lower.

[0091] In summary, the application provides a single battery and a battery pack. The insulating piece of the single battery is provided with at least two flow guide ribs on the side away from the top cover sheet, and each flow guide rib is distributed along the outer periphery of the second liquid injection hole. The flow guide ribs can improve the structural strength of the area around the second liquid injection hole and reduce the risk of deformation of the insulating piece. Moreover, the flow guide channel communicated with the second liquid injection hole is formed between the two adjacent flow guide ribs, and the flow guide channel can guide the electrolyte during the injection process, thus helping to ensure the injection efficiency. In addition, in the radial direction of the second liquid injection hole, the flow guide ribs protrude towards the second liquid injection hole, and the included angle θ between the first straight line and the second straight line satisfies: 10°≤θ≤150°. Not only can the flow guide channel between the two adjacent flow guide ribs have sufficient flow area, but also can guide the electrolyte injection, thus helping to ensure the injection efficiency and reduce the risk of blockage of the first liquid injection hole and the second liquid injection hole. In addition, the manufacturing difficulty of the flow guide ribs can be reduced, and the manufacturing cost of the single battery can be reduced.

[0092] The single battery and the battery pack provided by the application are described in detail above, and the principles and implementation modes of the application are described by applying specific examples. The above examples are only used to help understand the method of the application and its core idea; at the same time, for those skilled in the art, according to the idea of the application, the specific implementation mode and application range will be changed, and the above description should not be understood as a limitation of the application.

Claims

1. A single cell, characterized by, The single battery comprises: a shell having a receiving cavity; an electrode assembly arranged in the receiving cavity; a top cover sheet connected to one side of the shell and covering the receiving cavity, the top cover sheet being provided with a first liquid injection hole; an insulating piece connected to one side of the top cover sheet close to the electrode assembly, the insulating piece being provided with a second liquid injection hole in communication with the first liquid injection hole; and at least two flow guide ribs, each of the flow guide ribs being protruded from one side of the insulating piece away from the top cover sheet, and each of the flow guide ribs being spaced apart along the outer periphery of the second liquid injection hole so that a flow guide flow channel in communication with the second liquid injection hole is formed between two adjacent flow guide ribs. In the radial direction of the second liquid injection hole, the flow guide rib protrudes towards the second liquid injection hole, and the flow guide rib has an inner wall surface close to the second liquid injection hole. The single battery has a height direction and a reference plane perpendicular to the height direction. In the extension direction of the flow guide rib, the flow guide rib comprises a first end point and a second end point. In the height direction, the normal projection of the inner wall surface on the reference plane is a circular arc. The line connecting the normal projection of the first end point on the reference plane and the center of the circular arc is a first straight line. The line connecting the normal projection of the second end point on the reference plane and the center of the circular arc is a second straight line. The included angle between the first straight line and the second straight line is θ, and 10°≤θ≤150°.

2. The single battery according to claim 1, wherein the included angle θ between the first straight line and the second straight line satisfies 30°≤θ≤60°. In the radial direction of the second liquid injection hole, the flow guide rib is spaced apart from the second liquid injection hole.

3. The single cell according to claim 1 or 2, characterized by, 4. The single battery according to claim 3, wherein the diameter of the second liquid injection hole is D mm, and the minimum distance between the flow guide rib and the second liquid injection hole is a mm, and 0.01<a / D≤0.67 or 0.1<a / D<0.

45.

5. The single battery according to claim 3, wherein the minimum distance between the flow guide rib and the second liquid injection hole is a mm, and 0.2≤a≤2; or the diameter of the second liquid injection hole is D mm, and 3≤D≤18.

6. The single battery according to claim 1 or 2, wherein the single battery has a length direction, and the insulating piece is provided with a relief valve boss, and the relief valve boss and the at least two flow guide ribs are spaced apart along the length direction. In the length direction, the size of the top cover sheet is L mm, the minimum distance between the flow guide rib and the relief valve boss in the length direction is L1 mm, and 0.005≤L1 / L<1 or 0.005≤L1 / L≤0.

91.

7. The single battery according to claim 1 or 2, wherein the single battery has a length direction, and the insulating piece is provided with a relief valve boss, and the relief valve boss and the at least two flow guide ribs are spaced apart along the length direction. ​ ​ ​ ​ ​ ​ The minimum distance between the flow guide ribs and the anti-explosion valve boss in the length direction is L1 mm, and 3≤L1≤500 is satisfied; or, The size of the top cover sheet in the length direction is L mm, and 10≤L≤600 is satisfied. 8.The single battery according to claim 1 or 2, wherein, The single battery has a length direction; the single battery further comprises a pole post, the pole post is arranged on the top cover sheet and the insulating piece, and the pole post and the at least two flow guide ribs are distributed along the length direction at intervals; The size of the top cover sheet in the length direction is L mm, and the minimum distance between the flow guide ribs and the pole post for connecting the end portions of the electrode assembly in the length direction is L2 mm, and 0.006 9.The single battery according to claim 1 or 2, wherein, The single battery has a length direction; the single battery further comprises a pole post, the pole post is arranged on the top cover sheet and the insulating piece, and the pole post and the at least two flow guide ribs are distributed along the length direction at intervals; The minimum distance between the flow guide ribs and the pole post for connecting the end portions of the electrode assembly in the length direction is L2 mm, and 4≤L2≤500 is satisfied; or, The size of the top cover sheet in the length direction is L mm, and 10≤L≤600 is satisfied. 10.The single battery according to claim 1 or 2, wherein, The side of the flow guide rib facing the second liquid injection hole is provided with a through hole and / or a blind hole.

11. A battery pack, characterized by A battery pack comprising a box and the single battery according to any one of claims 1 to 10, wherein the single battery is arranged in the box.

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