CN220585338U - Cover plate, single battery and high-capacity battery - Google Patents

Abstract

The utility model discloses a cover plate, a single battery and a high-capacity battery. The cover plate comprises a cover plate body, and an annular groove is formed in the cover plate body. When the cylinder body and the cover plate of the single battery are welded, the annular groove structure can ensure the fit degree between the cylinder body and the cover plate, favorable conditions are provided for the welding of the subsequent cylinder body and the cover plate, and the annular groove can greatly digest or limit the impact and stress brought by extrusion assembly to the annular groove and the inner area defined by the annular groove, so that the adverse effect brought by external extrusion force is reduced or even blocked, and the reliability of the welding position during assembly is ensured.

Description

Cover plate, single battery and high-capacity battery

Technical Field

The utility model belongs to the field of batteries, and particularly relates to a cover plate, a single battery and a high-capacity battery.

Background

The uniformity of each single battery in the battery module is poor due to the fact that the single batteries in the battery module are different, and the cycle life of the battery module is directly limited, so that the uniformity of each single battery in the battery module is improved, and the focus and difficulty of research in the field are achieved.

Chinese patent, publication No. CN218525645U, discloses "a battery cell case, a battery cell, and a large-capacity battery". In this patent, the large-capacity battery includes a battery cell group formed by connecting a plurality of battery cells (also called batteries or single batteries) in parallel, and an electrolyte sharing channel formed by splicing the pipelines on the respective battery cell cases. After the electrolyte sharing channel is formed by pipeline splicing, electrolyte injected through the electrolyte injection mechanism enters the cell shell, so that all cells in the cell group are in a unified electrolyte environment, and the uniformity of the cell group can be effectively improved.

In this scheme, the lower apron of electric core is fixed in the barrel bottom through the welding mode, and the sharing passageway of high-capacity battery is led to the concatenation mode through the sub-pipeline on each electric core and is constituteed, because the welding between lower apron and the barrel to and the concatenation between the sub-pipeline all belongs to hard connection, two following problems can appear in the high-capacity battery manufacturing process:

firstly, the accumulation of processing and assembling errors can cause the problem of poor bonding performance of the welding surface of the lower cover plate and the cylinder body and unstable welding; secondly, when extrusion splicing is carried out on the sub-pipelines of all the single batteries, the extrusion force can influence the connection strength of the welding position, and then the problem that liquid leakage occurs in the sharing channel can occur.

Disclosure of Invention

In order to solve the problems that the bonding performance of the lower cover plate of each single battery and the welding surface of the cylinder body is poor and the welding is not firm due to the accumulation of processing and assembling errors of the conventional high-capacity battery, and the connection strength of a welding position is influenced due to extrusion force when sub pipelines of each single battery are extruded and spliced, so that the problem that a sharing channel is leaked is likely to occur.

The cover plate comprises a cover plate body, and an annular groove is formed in the cover plate body. The purpose of the annular groove is that when the cylinder and the cover plate of the single battery are welded, an elastic structure is added between the welding surfaces of the cylinder and the cover plate, the elastic structure can ensure the fit degree between the cylinder and the cover plate, favorable conditions are provided for the subsequent welding of the cylinder and the cover plate, the annular groove can digest or limit the impact and the stress brought by extrusion assembly to the annular groove and the defined inner area of the annular groove to a larger extent, the adverse effect brought by external extrusion force is reduced or even blocked, and the reliability of the welding position during assembly is ensured.

Further, when the cover plate is used as a lower cover plate of a single battery, the cover plate body is provided with a sub-pipeline, the sub-pipeline is communicated with the cover plate body through a first through hole, and the annular groove surrounds the first through hole.

Further, when the cover plate is used as an upper cover plate of a single battery, the cover plate body is provided with two second through holes, the two second through holes are positioned on two sides of the sub-pipeline, and the annular groove surrounds the first through hole and is positioned between the two second through holes.

Further, the groove depth of the annular groove is 40 to 50 percent of the thickness of the cover plate body, and the groove width is 1 to 1.5 times of the groove depth.

The second aspect of the present utility model provides a single battery, which is divided into the following three types:

first form: the single battery comprises an upper cover plate, a lower cover plate and a cylinder; the upper cover plate and the lower cover plate are respectively welded at two open ends of the cylinder; the lower cover plate is provided with a first sub-pipeline, a first through hole is formed between the first sub-pipeline and the lower cover plate, a first sealing mechanism is arranged at the first through hole, the lower cover plate is provided with a first annular groove, and the first annular groove surrounds the first through hole.

The single cells in the first form may constitute a large-capacity battery having a shared electrolyte system. The structure of the high-capacity battery is as follows: the battery pack comprises N single batteries which are arranged in parallel, wherein N is more than or equal to 2; the first sub-pipelines of all the single batteries form a first channel through splicing, and electrolyte areas in the inner cavities of all the single batteries are communicated through the first channel after the first sealing mechanism of all the single batteries is opened under the action of external force or electrolyte, so that electrolyte sharing is realized.

Second form: the single battery comprises an upper cover plate, a lower cover plate and a cylinder; the upper cover plate is provided with a second sub-pipeline, a third through hole is arranged between the second sub-pipeline and the upper cover plate, and a second sealing mechanism is arranged at the third through hole; two second through holes are formed in the upper cover plate and located on two sides of the second sub-pipeline, a second annular groove is formed in the lower cover plate, and the second annular groove surrounds the third through holes. The single cells of the second form may be used to form a high capacity battery having a gas balance system or explosion venting channels. The structure of the high-capacity battery is as follows: the battery pack comprises N single batteries which are arranged in parallel, wherein N is more than or equal to 2; the second sub-pipelines of the single batteries form a second channel through splicing;

after the inner cavities of the single batteries are opened under the action of external force or electrolyte, the gas areas of the inner cavities of the single batteries are communicated through the second channel, and then the single batteries realize gas balance;

or when the second sealing mechanism of each single battery is an explosion venting mechanism and is not opened, the second channel is used as an explosion venting channel of each single battery.

Third form: the single battery comprises an upper cover plate, a lower cover plate and a cylinder; the upper cover plate and the lower cover plate are respectively welded at two open ends of the cylinder; the lower cover plate is provided with a first sub-pipeline, a first through hole is formed between the first sub-pipeline and the lower cover plate, a first sealing mechanism is arranged at the first through hole, the lower cover plate is provided with a first annular groove, and the first annular groove surrounds the first through hole;

the upper cover plate is provided with a second sub-pipeline, a third through hole is arranged between the second sub-pipeline and the upper cover plate, and a second sealing mechanism is arranged at the third through hole; two second through holes are formed in the upper cover plate and located on two sides of the second sub-pipeline, a second annular groove is formed in the lower cover plate, and the second annular groove surrounds the third through holes. The single cells in the third form may constitute a large-capacity battery having both a shared electrolyte system and a gas balance system, or both a shared electrolyte system and an explosion venting channel. The structure of the high-capacity battery is as follows: the battery pack comprises N single batteries which are arranged in parallel, wherein N is more than or equal to 2; the first sub-pipelines of all the single batteries form a first channel through splicing, and electrolyte areas in the inner cavities of all the single batteries are communicated through the first channel after the first sealing mechanism of all the single batteries is opened under the action of external force or electrolyte, so that electrolyte sharing is realized;

the second sub-pipelines of the single batteries form a second channel through splicing;

after the inner cavities of the single batteries are opened under the action of external force or electrolyte, the gas areas of the inner cavities of the single batteries are communicated through the second channel, and then the single batteries realize gas balance;

or when the second sealing mechanism of each single battery is an explosion venting mechanism and is not opened, the second channel is used as an explosion venting channel of each single battery.

Drawings

Fig. 1 is a schematic structural view of a cover plate as a lower cover plate of a unit cell;

FIG. 2 is a schematic diagram of the structure of the cover plate as the upper cover plate of the unit cell;

FIG. 3 is a thermal diagram of a simulation analysis of a moment of couple applied to a cell top plate;

FIG. 4 is a simulated analytical heat map of deformation of the upper cover plate;

FIG. 5 is a simulated analytical heat map of deformation of an upper cover plate with an annular groove;

FIG. 6 is a simulated analytical heat map of the force applied when the upper cover plate is free of annular grooves;

FIG. 7 is a simulated analytical heat map of force applied when the upper cover plate has an annular groove;

fig. 8 is a structural view of a unit cell in example 1;

FIG. 9 is a partial cross-sectional view of the structure of FIG. 8;

fig. 10 is a schematic structural view of the large-capacity battery in embodiment 1;

fig. 11 is a structural view of a single cell in example 2;

FIG. 12 is a partial cross-sectional view of the structure of FIG. 11;

fig. 13 is a schematic view of the structure of a large-capacity battery in embodiment 2;

fig. 14 is a cross-sectional view of the unit cell of example 3;

fig. 15 is a schematic structural view of a large-capacity battery in example 3.

The reference numerals are as follows:

1-apron body, 2-sub-pipeline, 3-first through-hole, 4-annular groove, 5-second through-hole, 6-battery cell, 61-upper cover plate, 611-second sub-pipeline, 612-fourth through-hole, 613-second sealing mechanism, 614-second annular groove, 62-lower cover plate, 621-first sub-pipeline, 622-first sealing mechanism, 623-first annular groove, 624-third through-hole, 64-first passageway, 65-second passageway.

Detailed Description

The technical solutions of the embodiments will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are only some embodiments, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden, are within the scope of the present utility model based on the following examples.

Meanwhile, it should be noted that the positional or positional relationship indicated by the terms such as "upper, lower, inner and outer" and the like herein are based on the positional or positional relationship shown in the drawings, and are merely for convenience of description, and are not intended to indicate or imply that the apparatus or element to be referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the technical scheme. Furthermore, the terms "first, second, or third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The terms "mounted, connected, and coupled" should be construed broadly in this disclosure unless otherwise specifically indicated and defined, such as: can be fixedly connected, detachably connected or integrally connected: it may also be a mechanical connection, an electrical connection, or a direct connection, or may be indirectly connected through an intermediate medium, or may be a communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

The basic design idea of the utility model is as follows:

the cover plate is provided with an annular groove. When the cylinder body and the cover plate of the single battery are welded, the annular groove is equivalent to adding an elastic unloading structure between the welding surfaces of the cylinder body and the cover plate. The elastic unloading structure can ensure the fit degree between the cylinder body and the cover plate, provides favorable conditions for the subsequent welding of the cylinder body and the cover plate, and can greatly digest or limit the impact and stress caused by extrusion assembly to the annular groove and the defined inner area thereof, thereby reducing or even blocking the adverse effect caused by external extrusion force and ensuring the reliability of the welding position in the assembly process.

The shell of the single battery is mostly formed by welding an upper cover plate, a lower cover plate and a cylinder;

as shown in fig. 1, when the cover plate is used as a lower cover plate of a single battery, the cover plate body 1 is provided with a sub-pipeline 2, the sub-pipeline 2 is communicated with the cover plate body 1 through a first through hole 3, and the annular groove 4 surrounds the first through hole 3.

As shown in fig. 2, when the cover plate is used as an upper cover plate of a single battery, the cover plate body 1 is provided with a sub-pipeline 2 and two second through holes 5, the two second through holes 5 are located at two sides of the sub-pipeline 2, and the annular groove 4 surrounds the first through hole 3 and is located between the two second through holes 5.

The sub-pipeline 2 is used for splicing to form a shared channel of the high-capacity battery;

the purpose of the first through hole 3 is to mount the sealing mechanism.

The second through hole 5 serves to lead out the pole.

In order to verify the effect brought by the annular groove, the utility model also carries out the following simulation analysis:

as shown in fig. 3, a moment of couple of 195n.m is applied to both ends of the sub-pipe of the upper cover plate of the unit cell;

as shown in fig. 4, when the upper cover plate is not provided with the annular groove, the maximum deformation of the upper cover plate is approximately 0.15; as shown in fig. 5, when the upper cover plate has an annular groove, the maximum deformation of the upper cover plate is approximately 0.2; when the annular groove is opened, the compliance (inverse of stiffness) of the cover plate is increased by 33% ((0.2-0.15)/0.15) compared to when the annular groove is not opened. That is, the force application conditions are the same, and the cover plate with the annular groove has greater flexibility, so that the problem that the joint surface is difficult to be properly attached or assembled due to the accumulation of machining, welding and assembling errors can be solved.

As shown in fig. 6, when the upper cover plate is not provided with the annular groove, the maximum stress corresponding to the area provided with the annular groove on the cover plate is approximately 290Mpa; as shown in fig. 7, when the upper cover plate has an annular groove, the area maximum stress of the annular groove is approximately 457Mpa; from the simulation comparison results, the absorption stress ((457-290)/290) of the annular groove and the encircled area thereof is increased by 58% due to the annular groove. That is, the force application conditions are the same, and the annular groove can greatly digest or limit the impact and stress caused by extrusion assembly to the annular groove and the defined inner area thereof, thereby reducing or even blocking the adverse effect caused by external extrusion force and ensuring the reliability of the welding position.

According to simulation analysis and related design principles (golden section principle), when the depth of the annular groove is 40-50% of the thickness of the cover plate, the bearing rigidity and strength of the cover plate cannot be obviously influenced, and when the depth is more than 50%, the strength and rigidity of the cover plate can be greatly reduced.

According to the calculation formula of the rigidity, the rigidity of the cover plate is proportional to the cube of the thickness and proportional to the first power of the width. Therefore, the width of the annular groove is generally between 1 and 1.5 times the depth, and too wide a width can reduce the strength and rigidity of the substrate.

In addition, as can be seen from fig. 4 to 7, when the upper cover plate is stressed, deformation and stress are not conducted to the lower cover plate, and similarly, when the lower cover plate is stressed according to the davin principle, deformation and stress are not conducted to the upper cover plate. Therefore, the mutual influence of the upper cover plate and the lower cover plate is not needed to be considered in the simulation analysis.

Example 1

The embodiment provides a single battery, wherein the lower cover plate 61 of the single battery 6 adopts the design concept of the utility model, as shown in fig. 8 and 9, the whole single battery is similar to a commercial square lithium ion battery, and comprises an upper cover plate 61, a lower cover plate 62, a cylinder 63 and an electrode assembly (for conveniently displaying an annular groove, the electrode assembly is omitted in the figure); the upper cover plate 61 and the lower cover plate 62 are respectively welded at two open ends of the cylinder 63, the electrode assembly is positioned in the cylinder, and electrolyte is arranged in the cylinder; the electrode assembly is formed by sequentially arranging an anode, a diaphragm and a cathode and adopting lamination or winding technology; the lower cover plate 62 is provided with a first sub-pipeline 621, a third through hole 624 is arranged between the first sub-pipeline 621 and the lower cover plate 62, a first sealing mechanism 622 is arranged at the first through hole 624, the lower cover plate 62 is provided with a first annular groove 623, and the third through hole 624 is surrounded by the first annular groove 623.

The first sealing mechanism 622 in this embodiment is used to ensure the tightness of the single battery before the single battery does not form a large-capacity battery, so as to avoid the inner cavity of the single battery from being polluted by the outside; the electrolyte can be started under the action of electrolyte or external force in the process of forming the large-capacity battery by the single batteries, so that the electrolyte areas in the inner cavities of the single batteries are communicated through the sharing channel. The specific structure of the first sealing mechanism is disclosed in Chinese patent CN218525645U, CN 218525614U.

In this embodiment, the thickness of the lower cover plate is 3mm, the groove depth of the first annular groove 623 is 1.5mm, and the groove width is 1.8mm.

Based on a plurality of the unit cells of the present embodiment, a large-capacity battery having a shared electrolyte system, the specific structure of which is shown in fig. 10,

comprises N single batteries 6 which are arranged in parallel, wherein N=4 in the embodiment; the first sub-pipelines 621 of the single batteries 6 are spliced through connecting pieces to form a first channel 64, and after the first sealing mechanism 622 of each single battery is opened under the action of external force or electrolyte, the electrolyte areas of the inner cavities of the single batteries are communicated through the first channel 64, so that the electrolyte sharing of the single batteries is realized. One end of the first channel 64 is closed and the other end is operable to open an operating port of the first sealing mechanism, which is required to be sealed by a plug after the process of opening the first sealing mechanism is completed.

In other embodiments, the closed end of the first channel 64 may be provided with a liquid injection mechanism at the other end after the first sealing mechanism is opened, and the liquid injection mechanism injects electrolyte into the large-capacity battery in an initial stage to ensure continuity of the electrolyte in the shared electrolyte system (without liquid breaking), and may also inject the electrolyte into the large-capacity battery after a period of operation to complete staged repair of the large-capacity battery and improve cycle life of the large-capacity battery.

Example 2

The embodiment provides a single battery, wherein an upper cover plate 61 of the single battery 6 adopts the design concept of the utility model, as shown in fig. 11 and 12, the whole single battery is similar to a commercial square lithium ion battery, and comprises an upper cover plate 61, a lower cover plate 62, a cylinder 63 and an electrode assembly; the upper cover plate 61 and the lower cover plate 62 are respectively welded at two open ends of the cylinder, the electrode assembly is positioned in the cylinder, and electrolyte is arranged in the cylinder; the electrode assembly is formed by sequentially arranging an anode, a diaphragm and a cathode and adopting lamination or winding technology; the upper cover plate 61 is provided with a second sub-pipeline 611, a fourth through hole 612 is arranged between the second sub-pipeline 611 and the upper cover plate 61, and a second sealing mechanism 613 is arranged at the fourth through hole 612; two second through holes 5 are formed in the upper cover plate 61 and the two second through holes 5 are located on two sides of the second sub-pipeline 611, and a second annular groove 614 is formed in the lower cover plate 611, wherein the second annular groove 614 surrounds the fourth through hole 612.

The second sealing mechanism 613 in this embodiment has two forms and functions:

the first form is: before the single battery does not form a large-capacity battery, the tightness of the single battery is ensured, and the inner cavity of the single battery is prevented from being polluted by the outside; the gas area of the inner cavity of the single battery is communicated through the sharing channel when the single battery is opened under the action of electrolyte or external force in the process of forming the large-capacity battery. The specific structure of the first sealing mechanism is disclosed in Chinese patent CN218525645U, CN 218525614U.

Secondly, it is: the second sealing mechanism is an explosion venting mechanism (a commercially available explosion venting valve or explosion venting film) on the single battery, namely, before the single battery does not form a large-capacity battery, the tightness of the single battery is ensured, and the inner cavity of the single battery is prevented from being polluted by the outside; when the single battery is in thermal runaway, the explosion venting mechanism is started to discharge the thermal runaway smoke.

In this embodiment, the thickness of the lower cover plate is 3mm, the groove depth of the first annular groove 623 is 1.5mm, and the groove width is 1.8mm.

Based on a plurality of single batteries of the present embodiment, a large-capacity battery with a gas balance system or explosion venting channel can be assembled, and the specific structure of the large-capacity battery is shown in fig. 13:

the battery pack comprises N single batteries which are arranged in parallel, wherein N is more than or equal to 2; the battery pack comprises N single batteries which are arranged in parallel, wherein N is more than or equal to 2; the second sub-pipelines 611 of the single batteries 6 are spliced through connecting pieces to form a second channel 65;

after the battery is opened under the action of external force or electrolyte, the gas areas in the inner cavities of the single batteries are communicated through the second channel 65, so that the gas balance of the single batteries is realized; when the second channel 65 realizes the function, one end of the second channel 65 is a closed end, and the other end of the second channel can be provided with an exhaust valve, and the gas in each single battery can be regularly exhausted through the exhaust valve, so that a series of problems affecting the comprehensive performance of the large-capacity battery, such as the bulge of the single battery shell, caused by the incapability of exhausting the gas, are avoided.

Alternatively, when the second sealing mechanism 613 of each unit cell is an explosion venting mechanism and is not opened, the second channel is used as an explosion venting channel of each unit cell. When the second channel is used for realizing the function, one end of the second channel is a closed end, the other end of the second channel is connected with an external thermal runaway smoke treatment device, and the thermal runaway smoke treatment device can timely treat the thermal runaway smoke so as to avoid the influence on the external environment.

Example 3

The embodiment provides a single battery, wherein an upper cover plate 61 and a lower cover plate 62 of the single battery adopt the design concept of the utility model, as shown in fig. 14, the whole single battery is similar to a commercial square lithium ion battery, and comprises an upper cover plate 61, a lower cover plate 62, a cylinder 63 and an electrode assembly; the upper cover plate 61 and the lower cover plate 62 are welded to two open ends of the cylinder 63, respectively, the electrode assembly is positioned in the cylinder 63, and electrolyte is provided in the cylinder 63; the electrode assembly is formed by sequentially arranging an anode, a diaphragm and a cathode and adopting lamination or winding technology;

the lower cover plate 62 is provided with a first sub-pipeline 621, a third through hole 624 is arranged between the first sub-pipeline 621 and the lower cover plate, a first sealing mechanism 622 is arranged at the third through hole 624, the lower cover plate 62 is provided with a first annular groove 623, and the third through hole 624 is surrounded by the first annular groove 623.

The upper cover plate 61 is provided with a second sub-pipeline 611, a fourth through hole 612 is arranged between the second sub-pipeline 611 and the upper cover plate 61, and a second sealing mechanism 613 is arranged at the fourth through hole 612; two second through holes 5 are formed in the upper cover plate 61 and the two second through holes 5 are located on two sides of the second sub-pipeline 611, and a second annular groove 614 is formed in the lower cover plate 611, wherein the second annular groove 614 surrounds the fourth through hole 612.

The first sealing mechanism 622 in this embodiment is used to ensure the tightness of the single battery before the single battery does not form a large-capacity battery, so as to avoid the inner cavity of the single battery from being polluted by the outside; the electrolyte can be started under the action of electrolyte or external force in the process of forming the large-capacity battery by the single batteries, so that the electrolyte areas in the inner cavities of the single batteries are communicated through the sharing channel. The specific structure of the first sealing mechanism is disclosed in Chinese patent CN218525645U, CN 218525614U.

The second sealing mechanism 613 in this embodiment has two forms and functions:

the first form is: before the single battery does not form a large-capacity battery, the tightness of the single battery is ensured, and the inner cavity of the single battery is prevented from being polluted by the outside; the gas area of the inner cavity of the single battery is communicated through the sharing channel when the single battery is opened under the action of electrolyte or external force in the process of forming the large-capacity battery. The specific structure of the first sealing mechanism is disclosed in Chinese patent CN218525645U, CN 218525614U.

Secondly, it is: the second sealing mechanism is an explosion venting mechanism (a commercially available explosion venting valve or explosion venting film) on the single battery, namely, before the single battery does not form a large-capacity battery, the tightness of the single battery is ensured, and the inner cavity of the single battery is prevented from being polluted by the outside; when the single battery is in thermal runaway, the explosion venting mechanism is started to discharge the thermal runaway smoke.

The single battery based on the plurality of the present embodiments has both the shared electrolyte system and the gas balance system, or has both the shared electrolyte system and the explosion venting channel. The specific structure of the large-capacity battery is shown in fig. 15:

comprises N single batteries 6 which are arranged in parallel, wherein N is more than or equal to 2; the first sub-pipelines 611 of the single batteries 6 are spliced through the connecting piece to form a first channel 64, and the electrolyte areas of the inner cavities of the single batteries are communicated through the first channel after the first sealing mechanism 622 of the single batteries is opened under the action of external force or electrolyte, so that the electrolyte sharing of the single batteries is realized. One end of the first channel 64 is closed and the other end is operable to open an operating port of the first sealing mechanism, which is required to be sealed by a plug after the process of opening the first sealing mechanism is completed.

In other embodiments, the closed end of one end of the first channel and the other end of the first channel can be provided with a liquid injection mechanism after the opening process of the first sealing mechanism is completed, the liquid injection mechanism injects electrolyte into the high-capacity battery in an initial stage, ensures continuity of the electrolyte in the shared electrolyte system (the condition of no liquid interruption occurs), and can inject the electrolyte into the high-capacity battery after a period of operation so as to complete staged repair of the high-capacity battery and improve the cycle life of the high-capacity battery.

The second sub-pipelines 621 of the individual cells 6 form a second channel 65 by splicing;

after the battery is opened under the action of external force or electrolyte, the gas areas in the inner cavities of the single batteries are communicated through the second channel 65, so that the gas balance of the single batteries is realized; when the second channel 65 realizes the function, one end of the second channel 65 is a closed end, and the other end of the second channel can be provided with an exhaust valve, and the gas in each single battery can be regularly exhausted through the exhaust valve, so that a series of problems affecting the comprehensive performance of the large-capacity battery, such as the bulge of the single battery shell, caused by the incapability of exhausting the gas, are avoided.

Or when the second sealing mechanism of each single battery is an explosion venting mechanism and is not opened, the second channel is used as an explosion venting channel of each single battery. When the second channel is used for realizing the function, one end of the second channel is a closed end, the other end of the second channel is connected with an external thermal runaway smoke treatment device, and the thermal runaway smoke treatment device can timely treat the thermal runaway smoke so as to avoid the influence on the external environment.

In addition, it should be noted that the single battery in the above embodiments 1-3 may also take two other forms:

in the first form, the electrode assembly in the single battery is replaced by a commercially available square lithium ion battery, and the square lithium ion battery is provided with at least one opening, so that the inner cavities of the square lithium ion battery can be communicated with the first channel and the second channel after the first sealing mechanism and the second sealing mechanism are opened.

In the second form, the electrode assembly in the single battery is replaced by a plurality of parallel commercial soft package batteries, each commercial soft package battery is provided with at least one opening, and after the first sealing mechanism and the second sealing mechanism are opened, the inner cavities of all commercial soft package batteries can be communicated with the first channel and the second channel.

Claims (9)

1. The cover plate is characterized by comprising a cover plate body, wherein an annular groove is formed in the cover plate body; the cover plate body is provided with a sub-pipeline, the sub-pipeline is communicated with the cover plate body through a first through hole, and the annular groove surrounds the first through hole.

2. The cover plate according to claim 1, wherein the cover plate body is provided with two second through holes, the two second through holes are located at two sides of the sub-pipeline, and the annular groove surrounds the first through hole and is located between the two second through holes.

3. A cover plate according to claim 1 or 2, wherein the annular groove has a groove depth of 40% to 50% of the cover plate thickness and a groove width of 1 to 1.5 times the groove depth.

4. A single battery comprises an upper cover plate, a lower cover plate and a cylinder; the method is characterized in that: the upper cover plate and the lower cover plate are respectively welded at two open ends of the cylinder; the lower cover plate is provided with a first sub-pipeline, a first through hole is formed between the first sub-pipeline and the lower cover plate, a first sealing mechanism is arranged at the first through hole, the lower cover plate is provided with a first annular groove, and the first annular groove surrounds the first through hole.

5. A high-capacity battery, characterized by comprising N single batteries as claimed in claim 4 arranged in parallel, wherein N is more than or equal to 2; the first sub-pipelines of all the single batteries form a first channel through splicing, and electrolyte areas in the inner cavities of all the single batteries are communicated through the first channel after the first sealing mechanism of all the single batteries is opened under the action of external force or electrolyte, so that electrolyte sharing is realized.

6. A single battery comprises an upper cover plate, a lower cover plate and a cylinder; the method is characterized in that: the upper cover plate and the lower cover plate are respectively welded at two open ends of the cylinder; the upper cover plate is provided with a second sub-pipeline, a third through hole is arranged between the second sub-pipeline and the upper cover plate, and a second sealing mechanism is arranged at the third through hole; two second through holes are formed in the upper cover plate and located on two sides of the second sub-pipeline, a second annular groove is formed in the lower cover plate, and the second annular groove surrounds the third through holes.

7. A high-capacity battery, which is characterized by comprising N single batteries as claimed in claim 6 arranged in parallel, wherein N is more than or equal to 2; the second sub-pipelines of the single batteries form a second channel through splicing;

after the inner cavities of the single batteries are opened under the action of external force or electrolyte, the gas areas of the inner cavities of the single batteries are communicated through the second channel, and then the single batteries realize gas balance;

or when the second sealing mechanism of each single battery is an explosion venting mechanism and is not opened, the second channel is used as an explosion venting channel of each single battery.

8. A single battery comprises an upper cover plate, a lower cover plate and a cylinder; the method is characterized in that: the upper cover plate and the lower cover plate are respectively welded at two open ends of the cylinder; the lower cover plate is provided with a first sub-pipeline, a first through hole is formed between the first sub-pipeline and the lower cover plate, a first sealing mechanism is arranged at the first through hole, the lower cover plate is provided with a first annular groove, and the first annular groove surrounds the first through hole;

the upper cover plate is provided with a second sub-pipeline, a third through hole is arranged between the second sub-pipeline and the upper cover plate, and a second sealing mechanism is arranged at the third through hole; two second through holes are formed in the upper cover plate and located on two sides of the second sub-pipeline, a second annular groove is formed in the lower cover plate, and the second annular groove surrounds the third through holes.

9. A high-capacity battery, characterized by comprising N single batteries as claimed in claim 8 arranged in parallel, wherein N is more than or equal to 2; the first sub-pipelines of all the single batteries form a first channel through splicing, and electrolyte areas in the inner cavities of all the single batteries are communicated through the first channel after the first sealing mechanism of all the single batteries is opened under the action of external force or electrolyte, so that electrolyte sharing is realized;

the second sub-pipelines of the single batteries form a second channel through splicing;

after the inner cavities of the single batteries are opened under the action of external force or electrolyte, the gas areas of the inner cavities of the single batteries are communicated through the second channel, and then the single batteries realize gas balance;

or when the second sealing mechanism of each single battery is an explosion venting mechanism and is not opened, the second channel is used as an explosion venting channel of each single battery.