End cover assembly, battery monomer and battery pack

Abstract

The utility model relates to an end cover assembly, a battery monomer and a battery pack. The end cover assembly comprises an end cover, a guide cylinder and a buffer piece, the battery monomer comprises a shell, an electrode assembly and an end cover assembly, an electrolyte is injected into the shell through the liquid injection hole, the electrolyte enters the buffer piece through the guide cylinder, so that the impact of the electrolyte is buffered, and the battery monomer is prevented from being damaged. Then the electrolyte flows out of the guide cylinder and the buffer piece through the liquid outlet holes in the two sides of the first direction, and the two side walls, arranged in the first direction, of the shell are the two side walls, in the width direction of the end cover, of the shell, so that the liquid outlet holes are close to the two side walls, arranged in the first direction, of the shell; therefore, the electrolyte flowing out of the liquid outlet hole has a horizontal linear speed, can flow to the inner side wall of the shell, avoids the head of the roll core, directly flows to the bottom of the battery monomer and infiltrates from bottom to top, so that gas discharge is facilitated, and bubbles at the bottom of the battery monomer are reduced.

Description

Technical Field

[0001] The present application relates to the field of new energy battery technology, and in particular to end cover assemblies, battery cells, and battery packs. Background Art

[0002] With the development of the new energy industry, the demand for lithium-ion battery performance continues to increase. The process and structural design of electrolyte injection play a key role in this. Current lithium-ion batteries often use a secondary injection process, using one-shot and two-shot electrolytes with different formulas to achieve improvement and regulation of battery cell performance. The current injection port design of the battery cell top cover is usually a circular through hole, facing the head of the core roll. The first and second injections of electrolyte are injected from this injection port, and the injection is done through a negative pressure-positive pressure cycle. The electrolyte flow directly impacts the head of the core roll. There is a high-temperature infiltration step after the first injection, and direct capacity after the second injection.

[0003] In the prior art, such as in patent document CN214542473U: the baffle boss has a small area and is flat, and has no guiding effect. The liquid flow rebounds and flows out in a disorderly manner after impact, which may aggravate the bubble problem. Patent document CN219696571U has made some improvements on the above basis, but the baffle is V-shaped or semicircular, and the liquid flow will rebound to the middle to form turbulence and bubbles when it is blocked. The width of the baffle boss is still much smaller than the thickness of the winding core in the shell, and it cannot play a guiding role. After the electrolyte flows out, it will still start to infiltrate from the head of the battery cell, and the bubble problem in the winding core is difficult to improve.

[0004] In the above scheme, the electrolyte is first injected into the head of the battery cell, and then seeps down along the diaphragm. The excess electrolyte flows to the bottom along the outside and infiltrates upward by the capillary action of the diaphragm. During this process, the upward discharge of gas is blocked, and bubbles are easily generated, forming black spots or even lithium precipitation during formation. Utility Model Content

[0005] Based on this, it is necessary to provide an end cover assembly, a battery cell, and a battery pack to address the problem in the prior art that the electrolyte is first injected into the head of the battery cell and then seeps down along the diaphragm, and the excess electrolyte flows along the outside to the bottom and infiltrates upward by the capillary action of the diaphragm. In this process, the upward discharge of gas is blocked, bubbles are easily generated, and black spots and even lithium precipitation are formed during formation.

[0006] An end cap assembly is used to connect to an opening of a housing of a battery cell, the end cap assembly comprising:

[0007] An end cover, wherein the end cover is provided with a liquid injection hole;

[0008] a flow guide tube, one end of which is connected to the end cover and communicated with the liquid injection hole, the flow guide tube is located between two side walls of the shell arranged along a first direction, and liquid outlet holes are respectively provided on both sides of the flow guide tube along the first direction, and the first direction is the width direction of the end cover; and

[0009] A buffer component covers an opening of one end of the guide tube away from the end cover and is connected to the guide tube.

[0010] In one embodiment, the guide tube is a cylinder, the buffer component is a partial spherical shell, and a side of the buffer component close to the guide tube is recessed in a direction away from the guide tube.

[0011] In one embodiment, the guide tube is a square tube; the buffer member includes a buffer plate and two guide plates;

[0012] The guide plate is a partial circular plate, and the guide plate has an arc-shaped edge and a straight edge. The straight edges of the two guide plates are respectively connected to one end of the two side walls of the guide tube arranged in the first direction away from the end cover. The buffer plate is an arc-shaped plate, and the two sides of the buffer plate along the first direction are respectively connected to the arc-shaped edges of the two guide plates, and the two sides of the buffer plate along the second direction are respectively connected to one end of the two side walls of the guide tube along the second direction away from the end cover.

[0013] The second direction is the length direction of the end cover, and the first direction is perpendicular to the second direction.

[0014] In one embodiment, the end cover assembly further includes a lower plastic plate, the lower plastic plate is provided with a through hole, one side of the lower plastic plate is connected to the end cover, and the other side is connected to the guide tube, one end of the through hole is connected to the injection hole, and the other end is connected to the opening of the guide tube close to the end cover.

[0015] In one embodiment, the lower plastic plate, the guide tube and the buffer are integrally formed.

[0016] In one embodiment, the end cover assembly further includes two bosses, which are respectively connected to the two ends of the end cover along the second direction, and the bosses are located on one side of the end cover where the guide tube is set, the second direction is the length direction of the end cover, and the first direction is perpendicular to the second direction.

[0017] In one embodiment, the thickness of the boss along the third direction is equal to the sum of the lengths of the guide tube and the buffer member along the third direction, the third direction is the thickness direction of the end cover, and the first direction, the second direction and the third direction are perpendicular to each other.

[0018] In one embodiment, the inner walls of the guide tube and the buffer member are provided with a plurality of guide grooves or guide protrusions.

[0019] An embodiment of the present application further provides a battery cell, the battery cell comprising: a housing, an electrode assembly and the end cap assembly;

[0020] The housing is provided with a receiving cavity and an opening;

[0021] The electrode assembly is disposed in the accommodating cavity;

[0022] The end cover assembly is arranged to cover the opening of the shell, the guide tube and the buffer member.

[0023] An embodiment of the present application further provides a battery pack, comprising a box body and at least one of the above-mentioned battery cells, wherein the battery cell is located in the box body.

[0024] When the end cap assembly in the above-mentioned battery is assembled in the shell and used, the side of the end cap provided with the guide tube is facing the interior of the shell, the guide tube and the buffer are placed inside the shell and the end cap covers the opening of the shell, then the end cap is connected to the shell, and electrolyte is injected into the shell through the injection hole. The electrolyte enters the buffer through the guide tube, thereby buffering the impact of the electrolyte, and then the electrolyte flows out of the guide tube and the buffer through the outlet holes on both sides of the first direction. Since the two side walls of the shell arranged in the first direction are the two side walls in the width direction of the end cap, the distance between the outlet hole and the two side walls of the shell arranged in the first direction is relatively close, so that the electrolyte flowing out of the outlet hole has a horizontal linear velocity, and will flow to the inner wall of the shell, avoiding the head of the core and directly flowing into the bottom of the battery cell, infiltrating from bottom to top, which is conducive to gas discharge and reduces bubbles at the bottom of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of an end cover assembly according to an embodiment.

[0026] Figure 2 for Figure 1 Top view of the .

[0027] Figure 3 for Figure 1 Schematic diagram from another perspective.

[0028] Figure 4 FIG. 4 is a schematic diagram of a guide protrusion according to an embodiment.

[0029] Figure 5 Schematic diagram of a guide groove according to an embodiment.

[0030] Description of Figure Numbers:

[0031] 100-end cover assembly;

[0032] 110-end cover; 111-liquid injection hole; 112-lower plastic plate; 113-through hole; 114-boss; 115-guiding groove; 116-guiding protrusion;

[0033] 120- flow guide tube; 121- liquid outlet hole;

[0034] 130-buffer; 131-buffer plate; 132-guide plate;

[0035] OX-first direction; OY-second direction; OZ-third direction. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0037] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0038] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0039] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0040] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0041] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0042] See also Figure 1 , Figure 1 A schematic structural diagram of an end cap assembly 100 in an embodiment of the present application is shown. The end cap assembly 100 provided in an embodiment of the present application is used to connect to the opening of the shell of a battery cell. The end cap assembly 100 includes: an end cap 110, a guide tube 120 and a buffer member 130.

[0043] In the above-mentioned end cover assembly 100, the end cover 110 is provided with a liquid injection hole 111, one end of the guide tube 120 is connected to the end cover 110 and communicated with the liquid injection hole 111, the guide tube 120 is located between the two side walls of the shell arranged along the first direction OX, and the guide tube 120 is respectively provided with liquid outlet holes 121 on both sides along the first direction OX. The buffer member 130 covers the opening of the end of the guide tube 120 away from the end cover 110 and is connected to the guide tube 120. The first direction OX is the width direction of the end cover 110.

[0044] During the assembly and use of the end cap assembly 100, the end cap 110 is provided with a side of the guide tube 120 facing the inside of the shell, the guide tube 120 and the buffer 130 are placed inside the shell, and the end cap 110 covers the opening of the shell, and then the end cap 110 is connected to the shell, and the electrolyte is injected into the shell through the injection hole 111. The electrolyte enters the buffer 130 through the guide tube 120, thereby buffering the impact of the electrolyte, and then the electrolyte passes through the outlet on both sides of the first direction OX. The liquid hole 121 flows out of the guide tube 120 and the buffer member 130. Since the two side walls of the shell arranged along the first direction OX are the two side walls in the width direction of the end cover 110, the distance between the liquid outlet 121 and the two side walls of the shell arranged along the first direction OX is relatively close, so that the electrolyte flowing out of the liquid outlet 121 has a horizontal linear velocity and will flow to the inner wall of the shell, avoiding the head of the winding core and directly flowing into the bottom of the battery cell, infiltrating from bottom to top, which is conducive to gas discharge and reduces bubbles at the bottom of the battery cell.

[0045] See also Figure 1 In one embodiment, the guide tube 120 is a cylinder, and the buffer member 130 is a partial spherical shell. The side of the buffer member 130 close to the guide tube 120 is recessed in the direction away from the guide tube 120, so that the electrolyte flowing to the buffer member 130 along any radial direction of the guide tube 120 can flow to the bottom of the buffer member 130 along an arc trajectory when it flows to the connection between the guide tube 120 and the buffer member 130, thereby improving the buffering effect, reducing the liquid from bursting out directly from the liquid outlet 121 due to liquid impact, and further reducing bubbles caused by electrolyte bursting.

[0046] See also Figure 1-Figure 3 In one embodiment, the guide tube 120 is a square tube; the buffer member 130 includes a buffer plate 131 and two guide plates 132; the guide plate 132 is a partial circular plate, and the guide plate 132 has an arc edge and a straight edge, and the straight edges of the two guide plates 132 are respectively connected to the ends of the two side walls of the guide tube 120 arranged along the first direction OX away from the end cover 110, and the buffer plate 131 is an arc plate, and the two sides of the buffer plate 131 along the first direction OX are respectively connected to the arc edges of the two guide plates 132, and the two sides of the buffer plate 131 along the second direction OY are respectively connected to the two sides of the guide tube 120 along the second direction OY. The two side walls are connected at one end away from the end cover 110; the second direction OY is the length direction of the end cover 110, and the first direction OX is perpendicular to the second direction OY, so that the electrolyte entering the guide tube 120 flows along the inner wall of the guide tube 120 to the arc plate and the buffer plate 131, and then flows along the arc trajectory to the bottom of the buffer plate 131, and then gathers inside the guide tube 120 and the buffer member 130 until it flows out from the liquid outlet 121, thereby improving the buffering effect, reducing the liquid from bursting out directly from the liquid outlet 121 due to liquid impact, and further reducing bubbles caused by electrolyte bursting.

[0047] See also Figure 1 In one embodiment, the end cover assembly 100 further includes a lower plastic plate 112, which is provided with a through hole 113. One side of the lower plastic plate 112 is connected to the end cover 110, and the other side is connected to the guide tube 120. One end of the through hole 113 is connected to the injection hole 111, and the other end is connected to the opening of the guide tube 120 close to the end cover 110, so that the lower plastic and the end cover 110 as well as the guide tube 120 and the buffer 130 are directly integrated together and directly connected to the shell, thereby eliminating the need to separately design the lower plastic plate 112 assembled with the guide tube 120, the buffer 130 and the end cover 110.

[0048] In one embodiment, the lower plastic plate 112 , the guide tube 120 , and the buffer member 130 are integrally formed, thereby achieving structural integrity without the need for assembly of parts or panels, thereby improving the structural stability of the components.

[0049] See also Figure 1 In one embodiment, the end cover assembly 100 further includes two bosses 114, which are respectively connected to the two ends of the end cover 110 along the second direction OY. The boss 114 is located on one side of the end cover 110 where the guide tube 120 is provided. The second direction OY is the length direction of the end cover 110, and the first direction OX is perpendicular to the second direction OY, so that the boss 114 is connected or abutted with the internal structure of the shell, thereby improving the stability of the connection between the end cover assembly 100 and the battery cell.

[0050] See also Figure 1 In one embodiment, the thickness of the boss 114 along the third direction OZ is equal to the sum of the lengths of the guide tube 120 and the buffer member 130 along the third direction OZ. The third direction OZ is the thickness direction of the end cover 110. The first direction OX, the second direction OY and the third direction OZ are perpendicular to each other, that is, the boss 114 is flush with the side of the buffer member 130 away from the end cover 110, so as not to occupy additional space in the height direction of the battery cell and not affect the energy density.

[0051] See also Figure 4-5 In one embodiment, the inner walls of the guide tube 120 and the buffer member 130 are provided with a plurality of guide grooves 115 or guide protrusions 116, so as to enhance the infiltration of the injected electrolyte into the inner walls of the guide tube 120 and the buffer member 130, and the liquid flow forms diffuse reflection to avoid strong rebound of the electrolyte.

[0052] Specifically, the inner walls of the guide tube 120 and the buffer member 130 are provided with a plurality of guide grooves 115 and guide protrusions 116, and other structures may be provided to achieve electrolyte infiltration, and the structure and the combination of structures will not be described in detail here.

[0053] An embodiment of the present application further provides a battery cell, the battery cell comprising: a housing, an electrode assembly and an end cap assembly 100;

[0054] The shell is provided with a receiving cavity and an opening;

[0055] The electrode assembly is disposed in the accommodating cavity;

[0056] The end cover assembly 100 covers the opening of the housing, the guide tube 120 and the buffer member 130 .

[0057] When the end cap assembly 100 is assembled to the shell and used, the side of the end cap 110 provided with the guide tube 120 is directed toward the inside of the shell, the guide tube 120 and the buffer 130 are placed inside the shell, and the end cap 110 covers the opening of the shell, and then the end cap 110 is connected to the shell, and the electrolyte is injected into the shell through the injection hole 111. The electrolyte enters the buffer 130 through the guide tube 120, thereby buffering the impact of the electrolyte, and then the electrolyte passes through the first direction OX on both sides. The liquid outlet hole 121 flows out of the guide tube 120 and the buffer member 130. Since the two side walls of the shell arranged along the first direction OX are the two side walls in the width direction of the end cover 110, the distance between the liquid outlet hole 121 and the two side walls of the shell arranged along the first direction OX is relatively close, so that the electrolyte flowing out of the liquid outlet hole 121 has a horizontal linear velocity and will flow to the inner wall of the shell, avoiding the head of the winding core and directly flowing into the bottom of the battery cell, infiltrating from bottom to top, which is conducive to gas discharge and reduces bubbles at the bottom of the battery cell.

[0058] An embodiment of the present application further provides a battery, comprising a box and at least one battery cell, wherein the battery cell is located in the box.

[0059] When the end cap assembly 100 in the battery pack is assembled in the shell and used, the side of the end cap 110 provided with the guide tube 120 is directed to the inside of the shell, the guide tube 120 and the buffer 130 are placed inside the shell, and the end cap 110 covers the opening of the shell, and then the end cap 110 is connected to the shell, and the electrolyte is injected into the shell through the injection hole 111. The electrolyte enters the buffer 130 through the guide tube 120, thereby buffering the impact of the electrolyte, and then the electrolyte passes through the first direction OX The liquid outlet holes 121 on both sides flow out of the guide tube 120 and the buffer member 130. Since the two side walls of the shell arranged along the first direction OX are the two side walls in the width direction of the end cover 110, the distance between the liquid outlet holes 121 and the two side walls of the shell arranged along the first direction OX is relatively close, so that the electrolyte flowing out of the liquid outlet holes 121 has a horizontal linear velocity and will flow to the inner wall of the shell, avoiding the head of the winding core and directly flowing into the bottom of the battery cell, infiltrating from bottom to top, which is conducive to gas discharge and reduces bubbles at the bottom of the battery cell.

[0060] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. An end cap assembly for connecting to an opening of a housing of a battery cell, characterized in that: The end cap assembly comprises: An end cover, wherein the end cover is provided with a liquid injection hole; a flow guide tube, one end of which is connected to the end cover and communicated with the liquid injection hole, the flow guide tube is located between two side walls of the shell arranged along a first direction, and liquid outlet holes are respectively provided on both sides of the flow guide tube along the first direction, and the first direction is the width direction of the end cover; and A buffer component covers an opening of one end of the guide tube away from the end cover and is connected to the guide tube.

2. The end cap assembly according to claim 1, characterized in that: The guide tube is a cylinder, the buffer is a partial spherical shell, and a side of the buffer close to the guide tube is recessed in a direction away from the guide tube.

3. The end cap assembly according to claim 1, characterized in that: The guide tube is a square tube; the buffer member includes a buffer plate and two guide plates; The guide plate is a partial circular plate, and the guide plate has an arc-shaped edge and a straight edge. The straight edges of the two guide plates are respectively connected to one end of the two side walls of the guide tube arranged in the first direction away from the end cover. The buffer plate is an arc-shaped plate, and the two sides of the buffer plate along the first direction are respectively connected to the arc-shaped edges of the two guide plates, and the two sides of the buffer plate along the second direction are respectively connected to one end of the two side walls of the guide tube along the second direction away from the end cover. The second direction is the length direction of the end cover, and the first direction is perpendicular to the second direction.

4. The end cap assembly according to claim 1, characterized in that: The end cover assembly also includes a lower plastic plate, which is provided with a through hole. One side of the lower plastic plate is connected to the end cover, and the other side is connected to the guide tube. One end of the through hole is connected to the injection hole, and the other end is connected to the opening of the guide tube close to the end cover.

5. The end cap assembly according to claim 4, characterized in that: The lower plastic plate, the guide tube and the buffer are integrally formed.

6. The end cap assembly according to claim 1, characterized in that: The end cover assembly also includes two bosses, which are respectively connected to the two ends of the end cover along the second direction. The bosses are located on one side of the end cover where the guide tube is set. The second direction is the length direction of the end cover, and the first direction is perpendicular to the second direction.

7. The end cap assembly according to claim 6, characterized in that: The thickness of the boss along the third direction is equal to the sum of the lengths of the guide tube and the buffer member along the third direction. The third direction is the thickness direction of the end cover. The first direction, the second direction and the third direction are perpendicular to each other.

8. The end cap assembly according to claim 1, characterized in that: The inner walls of the guide tube and the buffer member are provided with a plurality of guide grooves or guide protrusions.

9. A battery cell, characterized in that: The battery cell comprises: a shell, an electrode assembly and an end cap assembly according to any one of claims 1 to 8; The housing is provided with a receiving cavity and an opening; The electrode assembly is disposed in the accommodating cavity; The end cover assembly is arranged to cover the opening of the shell, the guide tube and the buffer member.

10. A battery pack, characterized in that: The invention comprises a casing and at least one battery cell according to claim 9, wherein the battery cell is located in the casing.

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