CN116706361B

CN116706361B - Cylindrical battery and preparation method thereof

Info

Publication number: CN116706361B
Application number: CN202310967879.6A
Authority: CN
Inventors: 廖栋梁
Original assignee: Shenzhen Yixin New Energy Technology Co ltd
Current assignee: Shenzhen Yixin New Energy Technology Co ltd
Priority date: 2023-08-03
Filing date: 2023-08-03
Publication date: 2023-12-19
Anticipated expiration: 2043-08-03
Also published as: CN116706361A

Abstract

The embodiment of the invention discloses a cylindrical battery and a preparation method thereof, and relates to the technical field of new energy batteries, wherein the cylindrical battery comprises a shell and a sealing piece, and the shell comprises a first sealing part and a first air hole; the first air hole is formed in the first sealing portion, the sealing piece is arranged in the first sealing portion and made of elastic materials, the sealing piece is provided with a protruding portion, and the protruding portion is embedded into the first air hole. The battery has better tightness, and solves the problem that the traditional battery can explode when short circuit occurs, and the battery ejects the sealing structure to cause harm.

Description

Cylindrical battery and preparation method thereof

Technical Field

The invention relates to the technical field of new energy batteries, in particular to a cylindrical battery and a preparation method thereof.

Background

With the development of society, people's life is increasingly electronic and intelligent, and energy storage devices are becoming more important. At present, conventional lithium batteries are divided into steel-shell cylindrical batteries, square batteries and soft-pack batteries according to packaging modes. The cylindrical battery is widely used in electric vehicles, energy storage, digital and consumer products at present due to high standardization degree. The steel-shell cylindrical battery can be further classified into a steel-shell cylindrical battery, a steel-shell button battery and an aluminum-shell capacitor battery (the steel-shell cylindrical battery is commonly known in the industry, but other materials can be used as a shell, such as aluminum).

The difference between the capacitive cylindrical battery and the steel shell cylindrical battery is that: the steel shell battery is provided with a sealing layer with a complex structure (also called an explosion-proof valve, a complex explosion-proof structure formed by combining a plurality of materials and accessories); the capacitor battery adopts the capacitor structure to prepare, and changes a complex explosion-proof structure into a simple explosion-proof plug structure (a plastic rubber sleeve with two holes) and an explosion-proof indentation with a concave bottom (for example, a cross, Y-shaped and H-shaped explosion-proof groove).

The current batteries of these two cylindrical structures each have their own drawbacks: firstly, the steel shell battery can explode, and once the explosion-proof valve of the steel shell battery fails, the steel shell battery explodes and has high power; secondly, the explosion-proof structure of the steel shell battery is not waterproof; thirdly, the explosion-proof plug at the top of the capacitor battery at high and low temperatures easily leaks electrolyte and allows external air to enter the battery; fourth, when the capacitor battery is in internal short circuit, the packaged aluminum shell has a girdle sealing structure, so that the battery cannot be decompressed through the explosion-proof rubber plug at the top of the battery, but is exploded through the explosion-proof structure at the bottom of the battery, and the explosion of the battery is caused; fifth, the top rubber plug of the capacitive cell has poor waterproof properties.

Disclosure of Invention

The embodiment of the invention solves the problem that the sealing structure of the traditional battery is easy to pop up to cause damage.

In order to solve the above problems, an embodiment of the present invention discloses a cylindrical battery. Has better sealing performance.

In a first aspect, the present invention provides a cylindrical battery comprising a housing including a first seal portion and a first air hole, and a seal; the first air hole is formed in the first sealing portion, the sealing piece is arranged in the first sealing portion and made of elastic materials, the sealing piece is provided with a protruding portion, and the protruding portion is embedded into the first air hole.

The casing still includes receipts bight and holding portion, first sealing portion with the holding portion slope is connected, first sealing portion with receive bight to be connected.

The further technical proposal is that the inclination angle of the first sealing part and the containing part is 135-179 degrees.

The cylindrical battery further comprises a fixing piece, wherein the fixing piece is provided with a buffer air bag, and the fixing piece is connected with the sealing piece.

The further technical scheme is that the shell further comprises a concave part, and the concave part is respectively connected with the first sealing part and the accommodating part.

The diameter of the fixing piece is smaller than the inner diameter of the sealing part, and the diameter of the fixing piece is smaller than the inner diameter of the concave part.

The cylindrical battery further comprises a core body and a first tab, wherein the core body is arranged in the shell, the first tab is provided with a clamping part, and the first tab penetrates through the sealing piece of the cylindrical battery and is connected with the core body.

The further technical scheme is that the coefficient of thermal expansion and contraction of the sealing piece of the cylindrical battery is equal to that of the core body.

The cylindrical battery further comprises a plurality of sealing pieces, the core body comprises a second electrode lug and a third electrode lug, the shell further comprises a second sealing part and a second air hole, the first sealing part and the second sealing part are respectively connected with the containing part, the second air hole is formed in the second sealing part, the sealing pieces are respectively arranged in the first sealing part and the second sealing part, the first sealing part is arranged around the periphery of the second electrode lug, and the second sealing part is arranged around the periphery of the third electrode lug.

The further technical scheme is that the second sealing part is obliquely connected with the containing part.

The cylindrical battery further comprises a plurality of sealing elements, and the sealing elements are stacked in the first sealing part.

The further technical scheme is that the first air holes are arranged around the periphery of the first sealing part and are provided with a plurality of rows.

The sealing piece is further provided with a blocking head part, and the blocking head part is connected with the protruding part and is arranged on the groove.

The further technical scheme is that the number of the plug parts is multiple, and part of the plug parts are connected.

The thickness of the sealing piece is smaller than or equal to 1mm.

The cylindrical battery further comprises a first mark and a second mark, wherein the first mark and the second mark are arranged on the sealing element.

In a second aspect, the present invention also provides a method for preparing a cylindrical battery, the method comprising:

s1, preparing a shell, and placing a preset core body in the shell;

s2, injecting a first liquid packaging material into the first sealing part of the shell and the first air hole of the shell, waiting for the first liquid packaging material to be solidified to obtain a sealing piece, wherein the sealing piece surrounded by the first air hole is a protruding part.

The core body comprises a full tab, and in the step S1, the surface of the full tab is coated with a second liquid packaging material.

The further technical scheme is that after the step S2, the method further comprises the following steps:

s3, exhausting the gas in the cavity formed by the shell and the sealing piece;

s4, injecting a third liquid packaging material into the first sealing part of the shell, and waiting for the third liquid packaging material to be solidified to obtain the sealing piece.

Compared with the prior art, the technical effects achieved by the embodiment of the invention include:

the air hole is reserved on the shell, the elastic deformation capability of the sealing element is utilized, when the air pressure in the cylindrical battery is increased, the sealing element deforms to enable the air hole to be communicated with the inside of the cylindrical battery after the air pressure of the air pressure on the sealing element reaches the deformation threshold of the sealing element, and then the air is released to realize pressure relief; or when the air pressure in the cylindrical battery is suddenly increased, the air pressure of the air pressure on the sealing element exceeds the deformation force threshold value of the sealing element instantaneously, the sealing element can deform and bulge towards the opening of the shell, and in the deformation and bulge process of the sealing element, the air hole is communicated with the interior of the cylindrical battery, so that the pressure release is realized by releasing the air, and the sealing element is prevented from being ejected. The phenomenon that the explosion occurs due to the increase of the air pressure in the cylindrical battery is effectively avoided. The structure of the sealing member is simpler than the conventional explosion-proof structure, and the cylindrical battery has good explosion resistance and can reduce the manufacturing cost of the cylindrical battery.

Compared with the prior art, the battery provided by the embodiment of the invention has the following technical effects:

firstly, the sealing function and the most important function of the sealing layer isolate the inside and the outside of the battery, and the sealing layer of the battery must have good sealing performance because electrolyte in the battery or the capacitor easily reacts with moisture and oxygen in the air; secondly, the explosion-proof effect, because battery or electric capacity are energy storage device, inside a large amount of energy storage, the inside of this device can produce high pressure when short circuit, and sealed battery is the metal casing, consequently the sealing layer just needs to have explosion-proof pressure release's effect, because traditional explosion-proof valve is expensive, the sealing layer only has sealed effect not explosion-proof effect on some low-end steel shell batteries. The traditional steel shell cylindrical battery has a complex sealing and explosion-proof structure and is expensive, while the capacitive battery is sealed in the form of a beam waist and a rubber plug, electrolyte is easy to leak at high temperature, and explosion can occur when short circuit occurs. Accordingly, the present application proposes a cylindrical battery with a check valve (i.e., a seal) of a self-repairing structure to improve the safety and waterproof properties of the battery.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of a cylindrical battery according to an embodiment of the present invention;

fig. 2 is a schematic cross-sectional structure of a cylindrical battery according to an embodiment of the present invention;

fig. 3 is a schematic cross-sectional structure of a cylindrical battery according to an embodiment of the present invention;

fig. 4 is a schematic cross-sectional structure of a cylindrical battery according to an embodiment of the present invention;

fig. 5 is a schematic cross-sectional structure of a cylindrical battery according to an embodiment of the present invention;

fig. 6 is a schematic cross-sectional structure of a cylindrical battery according to an embodiment of the present invention;

fig. 7 is a schematic cross-sectional structure of a cylindrical battery according to an embodiment of the present invention;

fig. 8 is a schematic cross-sectional structure of a cylindrical battery according to an embodiment of the present invention;

fig. 9 is a schematic structural view of a cylindrical battery according to an embodiment of the present invention;

fig. 10 is a schematic structural view of a cylindrical battery according to an embodiment of the present invention;

fig. 11 is a schematic structural view of a cylindrical battery according to an embodiment of the present invention;

fig. 12 is a schematic cross-sectional structure of a cylindrical battery according to an embodiment of the present invention;

fig. 13 is a partially enlarged view of a sectional structure of a cylindrical battery according to an embodiment of the present invention;

FIG. 14 is a schematic view of a core according to an embodiment of the present invention;

fig. 15 is a schematic structural diagram of a second ear according to an embodiment of the present invention;

fig. 16 is a schematic structural view of a third ear according to an embodiment of the present invention;

fig. 17 is a schematic flow chart of a method for manufacturing a cylindrical battery according to an embodiment of the present invention;

fig. 18 is a schematic flow chart of a method for manufacturing a cylindrical battery according to an embodiment of the present invention.

Reference numerals

The shell 1, the sealing element 2, the first sealing part 11, the first air hole 12, the accommodating part 13, the fixing element 3, the buffer air bag 31, the second sealing part 14, the second air hole 15, the concave part 16, the corner collecting part 17, the first mark 41, the second mark 42, the core body 5, the second lug 51, the third lug 52, the first lug 6, the clamping part 61, the protruding part 71, the blocking part 72 and the groove 8.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, in which like reference numerals represent like components. It will be apparent that the embodiments described below are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be understood that the terms "comprises" and "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the embodiments of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments of the invention. As used in the specification of the embodiments of the invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Referring to fig. 1-16, an embodiment of the present invention provides a cylindrical battery. The cylindrical battery includes a case 1 and a sealing member 2. The specific description of each component is as follows:

in the present embodiment, the housing 1 includes a first sealing portion 11 and a first air hole 12; the first air hole 12 is formed in the first sealing portion 11, the sealing member 2 is made of an elastic material, the sealing member 2 is provided with a protruding portion 71, and the protruding portion 71 is embedded in the first air hole 12.

Specifically, the first sealing portion 11 refers to a part of the housing 1 on the housing 1, and the first sealing portion 11 of the housing 1 is provided with a plurality of first air holes 12, and all the first air holes 12 are arranged around the sealing member 2. The sealing element 2 is made of elastic materials obtained by liquid pouring and waiting solidification, and has the characteristic of deformation when external force is applied to the sealing element. When the liquid is poured, the liquid fills the first air hole 12, and the sealing element 2 filled in the first air hole 12 after solidification is the protruding part 71 of the sealing element 2.

In a conventional state, the sealing member 2 is closely adhered to the inner wall of the case 1, thus blocking the communication of the first air hole 12 with the inside of the cylindrical battery. When the air pressure in the cylindrical battery is increased, after the air pressure generated by the air pressure on the sealing element 2 reaches the deformation force threshold of the sealing element 2, the sealing element 2 deforms so that a gap exists between the sealing element 2 and the inner wall of the shell 1, and a gap exists between the sealing element 2 and the inner wall of the first air hole 12, so that air can be discharged to the outside from the interior of the cylindrical battery through the gap and pass through the first air hole 12, and the effect of air leakage and pressure reduction in the interior of the cylindrical battery is realized. In an embodiment, the magnitude of the deformation force threshold of the seal 2 may be influenced by the thickness of the seal 2, the higher the thickness of the seal 2, the greater the deformation force threshold of the seal 2; the lower the thickness of the seal 2, the smaller the deformation force threshold of the seal 2.

The working process of the cylindrical battery is as follows:

the inside of the cylindrical battery is provided with a preset air release device, the air release device releases air to ensure that the air pressure in the cylindrical battery is increased, the air pressure generated by the air pressure on the sealing element 2 is increased along with the increase of the air pressure, and when the air pressure generated by the air pressure on the sealing element 2 does not reach the deformation force threshold value of the sealing element 2, the sealing element 2 blocks the communication between the first air hole 12 and the inside of the cylindrical battery, so that the air in the cylindrical battery is prevented from leaking outside; when the deflation device abnormally discharges a large amount of gas, the gas pressure generated by the gas pressure on the sealing element 2 reaches the deformation force threshold value of the sealing element 2, the sealing element 2 deforms so that a gap exists between the sealing element 2 and the inner wall of the shell 1, the gap exists between the sealing element 2 and the inner wall of the first gas hole 12, and the gas can be discharged to the outside from the inside of the cylindrical battery through the gap and passes through the first gas hole 12, so that the effect of gas leakage and pressure reduction in the inside of the cylindrical battery is realized.

The complex explosion-proof structure is not required to be additionally arranged, the air hole is reserved in the shell 1, the elastic deformation capability of the sealing element 2 is utilized, when the air pressure in the cylindrical battery is increased, the air pressure of the air pressure on the sealing element 2 reaches the deformation threshold value of the sealing element 2, and the sealing element 2 deforms to enable the air hole to be communicated with the interior of the cylindrical battery, so that the air is released to realize pressure relief; or, when the air pressure in the cylindrical battery is rapidly increased, the air pressure of the air pressure on the sealing element 2 exceeds the deformation force threshold value of the sealing element 2 instantly, the sealing element 2 can deform and bulge towards the opening of the shell 1 (see fig. 3), and in the deformation and bulge process of the sealing element 2, the air hole is communicated with the interior of the cylindrical battery, so that the release gas is released to realize pressure relief, and the sealing element 2 is prevented from being ejected. The phenomenon that the explosion occurs due to the increase of the air pressure in the cylindrical battery is effectively avoided. The structure of the sealing member 2 is simpler than that of the conventional explosion-proof structure, the cylindrical battery has good explosion-proof performance, and compared with the conventional explosion-proof valve, the cylindrical battery has the advantages that the failure can not be exploded, and the cost of the explosion-proof valve can be saved so as to reduce the manufacturing cost of the cylindrical battery. It should be noted that, in an embodiment, the capacitor is similar to a battery, and the capacitor is prepared to have explosion-proof performance and sealing performance, and it is understood that the housing 1, the sealing member 2, the first air hole 12 and the first sealing portion 11 may be applied to the capacitor, so that the capacitor has good sealing performance and explosion-proof performance, and compared with a traditional explosion-proof valve, the capacitor has no explosion due to failure, and the cost of the explosion-proof valve is saved to reduce the manufacturing cost of the capacitor.

In this embodiment, the housing 1 further includes a corner receiving portion 17 and a receiving portion 13, the first sealing portion 11 is obliquely connected to the receiving portion 13, and the first sealing portion 11 is connected to the corner receiving portion 17.

The corner 17 is a region of the housing 1, which is formed by stamping a part of the housing 1, and it should be noted that the stamping process is specifically determined by referring to the existing information, and the present invention is not particularly limited to this, and is used to narrow the opening of the housing 1 and prevent the seal member 2 from coming out from the opening of the housing 1. The housing 13 is a part of the casing 1 surrounding the area to be obtained for the placement of the preset deflation means. When the first sealing part 11 is connected with the accommodating part 13 in a straight manner, the sealing member 2 cannot rebound after being deformed, and therefore, the cylindrical battery cannot recover the sealing effect after the sealing member 2 is deformed. When the first sealing part 11 is connected with the accommodating part 13 in an inclined manner, under the action of the inclined inner wall of the casing 1, the sealing part 2 can rebound to a state before deformation after deformation, namely, the sealing part 2 is closely attached to the inner wall of the casing 1, the sealing part 2 is closely attached to the inner wall of the first air hole 12, and the communication between the first air hole 12 and the interior of the cylindrical battery is blocked.

The inner diameter of the first sealing part 11 near one end of the accommodating part 13 is equal to the inner diameter of the accommodating part 13, and the inner diameter of the first sealing part 11 gradually decreases from one end near the accommodating part 13 to one end far away from the accommodating part 13, so that a structure with a narrow upper part and a wide lower part of the first sealing part 11 is obtained, namely the first sealing part 11 is obliquely connected with the accommodating part 13, on one hand, the sealing element 2 can be effectively ensured not to separate from the inside of the shell 1 in the normal state, and the sealing performance of the cylindrical battery is improved; on the other hand, the included angle between the inner wall of the first sealing portion 11 and the inner wall of the accommodating portion 13 may be changed to adjust the deformation force threshold of the sealing member 2, where the larger the included angle between the inner wall of the sealing portion and the inner wall of the accommodating portion 13 is, the lower the deformation force threshold of the sealing member 2 is, and the smaller the included angle between the inner wall of the sealing portion and the inner wall of the accommodating portion 13 is, the higher the deformation force threshold of the sealing member 2 is.

Further, the cylindrical battery further includes a plurality of sealing members 2, and the plurality of sealing members 2 are stacked in the first sealing portion 11.

Specifically, the cylindrical battery includes a multi-layered structure composed of a plurality of sealing members 2 stacked, and in one embodiment, the cylindrical battery is composed by stacking sealing members 2 of different sizes so that the sealing members 2 are more closely attached to the inner wall of the case 1, improving sealability.

Further, the thickness of the seal 2 is less than or equal to 1mm.

Specifically, the thickness of the sealing member 2 is less than or equal to 1mm, and the cylindrical battery package gives a battery having a higher energy density than a conventional explosion-proof structure.

Further, a first mark 41 and a second mark 42 are further included, and the first mark 41 and the second mark 42 are both arranged on the sealing element 2.

Specifically, the surface of the sealing member 2 may be colored, the first mark 41 and the second mark 42 are respectively an area on the sealing member 2, in one embodiment, the cylindrical battery is applied to a capacitive battery, the first mark 41 is red, the second mark 42 is black, the first mark 41 is arranged on the sealing member 2 in the positive electrode area, and the second mark 42 is arranged on the sealing member 2 in the negative electrode area so as to distinguish the positive electrode from the negative electrode of the capacitive battery.

Further, the cylindrical battery further comprises a fixing member 3, the fixing member 3 is provided with a buffer airbag 31, and the fixing member 3 is connected with the sealing member 2.

Specifically, the fixing piece 3 is made of hard materials, the buffer airbag 31 on the fixing piece 3 is used for enlarging the internal space of the cylindrical battery, the buffer airbag 31 is a groove of the fixing piece 3, or the buffer airbag 31 is a cavity with elasticity and is used for increasing the volume of gas stored in the shell 1, the volume of the gas stored in the shell 1 is increased to reduce the gas density in the shell 1, and then the pressure is reduced, so that the service life of the sealing piece 2 can be effectively prolonged.

Further, the inclination angle between the first sealing part 11 and the accommodating part 13 is 135 ° -179 °.

Specifically, the inclination angle of the first sealing portion 11 and the accommodating portion 13 refers to an included angle formed by an inner wall of the first sealing portion 11 and an inner wall of the accommodating portion 13, that is, an included angle a in the drawing, in an embodiment, the value range of the included angle a is 135 ° -179 ° to effectively ensure that the sealing member 2 has a rebound effect, wherein the magnitude of the included angle a affects the rebound frequency of the sealing member 2, and when the larger the angle of the included angle a is, the smaller the rebound frequency of the sealing member 2 is; the smaller the angle of included angle a, the more the seal 2 rebounds.

Further, the battery pack further comprises a core body 5 and a first tab 6, wherein the core body 5 is arranged in the cylindrical battery, the first tab 6 is provided with a clamping portion 61, and the first tab 6 penetrates through the sealing piece 2 of the cylindrical battery and is connected with the core body 5.

Specifically, the core body 5 is disposed in the accommodating portion 13 of the housing 1, and the core body 5 is also called as a winding core and a stacking core, and is used for performing chemical reaction discharge and discharging gas, so that the cylindrical battery can effectively avoid explosion caused by a large amount of gas generated when the core body 5 is short-circuited. The first tab 6 refers to a positive electrode and a negative electrode for connection with the core 5, in an embodiment, the first tab 6 includes a positive electrode lead and a negative electrode lead of a battery, and the shape of the clamping portion 61 includes an S-shape, an L-shape, and a loop shape, where the first tab 6 passes through the sealing element 2 to be connected with the core 5, the clamping portion 61 is disposed at a portion of the first tab 6 that does not pass through the sealing element 2, and the clamping portion 61 of the first tab 6 is used for fixing a position of the sealing element 2 in the housing 1, so that when a large amount of gas is generated when the core 5 is shorted, damage to the outside caused by the sealing element 2 bouncing out of the housing 1 is avoided.

Further, the first air holes 12 are arranged around the periphery of the first sealing portion 11, and are provided with a plurality of rows.

Specifically, the first air hole 12 is formed by punching the housing 1, and it should be noted that the punching process can be specifically determined by referring to the existing data, which is not specifically limited to the present invention. The first air holes 12 are arranged at equal intervals on the first sealing portion 11, and in one embodiment, the first sealing portion 11 is provided with two rows of first air holes 12, and a plurality of the sealing members 2 are stacked in the first sealing portion 11, so that each layer of sealing members 2 respectively blocks each row of first air holes 12 in a normal state.

In an embodiment, the sealing element 2 and the fixing element 3 are made of different materials, wherein one surface of the sealing element 2 is used for contacting with the outside, and can be coated with wear-resistant materials to achieve the wear-resistant effect; the fixing member 3 is used for supporting and connecting the sealing member 2 and the core 5, and is made of a material with hardness of more than 60 HRC; the buffer airbag 31 of the fixing member 3 is used for relieving the expansion of the gas generated by the operation of the preset air release device, and the gas can enter the gap between the sealing member 2 and the fixing member 3, so that the expansion of the gas generated by the operation of the preset air release device can be further relieved, in one embodiment, the expansion of the gas is relieved, so that the gas pressure is reduced, the gas pressure in the battery is reduced, the resistance of the core 5 is reduced, and the cylindrical battery obtained by the buffer airbag has the effect of lower internal resistance.

Further, the housing 1 further includes a recess 16, and the recess 16 is connected to the first sealing portion 11 and the accommodating portion 13, respectively.

Specifically, the housing 1 may be punched to obtain the recess 16, and the sealing member 2 may be further reinforced by the recess 16 in the first sealing portion 11, and in an embodiment, the recess 16 is further used for connection with the fixing member 3.

Further, the diameter of the fixing member 3 is smaller than the inner diameter of the sealing portion, and the diameter of the fixing member 3 is smaller than the inner diameter of the recess portion 16.

Specifically, the fixing member 3 is used for supporting and connecting the sealing member 2, and the sealing member 2 needs to be deformed to achieve the explosion-proof effect, and typically, the diameter of the fixing member 3 is 5% smaller than the minimum inner diameter of the housing 1, and in an embodiment, the minimum inner diameter of the housing 1 refers to the inner diameter of the sealing portion, or the minimum inner diameter of the housing 1 refers to the inner diameter of the recess portion 16 of the housing 1. The diameter of the fixing piece 3 is smaller than the minimum inner diameter of the shell 1, so that the sealing piece 2 is deformed, and finally, the explosion-proof effect is achieved.

In an embodiment, the housing 1 is provided with a recess 16, and the recess 16 is formed by stamping the housing 1, and it should be noted that the stamping process is specifically determined by referring to the existing data, which is not particularly limited in the present invention. The first sealing part 11 is connected with the accommodating part 13 in an inclined manner, when the first sealing part 11 is connected with the accommodating part 13 in an inclined manner, under the action of the inclined inner wall of the shell 1, the sealing part 2 can rebound to a state before deformation after deformation, namely, the sealing part 2 is closely attached to the inner wall of the shell 1, the sealing part 2 is closely attached to the inner wall of the first air hole 12, the communication between the first air hole 12 and the inside of the cylindrical battery is blocked, and the concave part 16 can effectively strengthen the sealing part 2 in the first sealing part 11, so that the sealing part 2 can rebound in time after deformation, namely, the effect of the one-way valve with the self-repairing structure is achieved.

Further, the thermal expansion coefficient and the cold contraction coefficient of the sealing member 2 of the cylindrical battery are equal to those of the core body 5.

Specifically, the coefficient of thermal expansion and contraction refers to the thermal expansion and contraction performance of the material, and the coefficient of thermal expansion and contraction of the sealing member 2 can be adjusted to be equal to the coefficient of thermal expansion and contraction of the core body 5, so that the sealing member 2 and the core body 5 have the same thermal expansion and contraction performance at different temperatures, and the safety of the cylindrical battery is improved.

Further, the core 5 includes a second ear 51 and a third ear 52, the housing 1 further includes a second sealing portion 14 and a second air hole 15, the first sealing portion 11 and the second sealing portion 14 are respectively connected with the accommodating portion 13, the second air hole 15 is disposed on the second sealing portion 14, the sealing member 2 is respectively disposed in the first sealing portion 11 and the second sealing portion 14, the first sealing portion 11 is disposed around the second ear 51, and the second sealing portion 14 is disposed around the third ear 52.

The second sealing portion 14 is connected to the housing portion 13 in an inclined manner.

In an embodiment, the core 5 is a full-tab core, including a core, a second tab 51 and a third tab 52, the second tab 51 is a positive electrode of the full-tab core, the third tab 52 is a negative electrode of the full-tab core, see fig. 12, the second tab 51 and the third tab 52 are respectively disposed at two ends of the core, two ends of the accommodating portion 13 are respectively provided with a first sealing portion 11 and a second sealing portion 14, the second sealing portion 14 is a part of the housing 1 on the housing 1, the second sealing portion 14 of the housing 1 is provided with a plurality of second air holes 15, and all the second air holes 15 are around the periphery of the sealing member 2. The sealing element 2 is made of elastic materials obtained by liquid pouring and waiting solidification, and has the characteristic of deformation when external force is applied to the sealing element. When the liquid is poured, the liquid fills the second air hole 15, and the sealing element 2 filled in the second air hole 15 after solidification is the protruding part 71 of the sealing element 2. When the second sealing part 14 is connected with the accommodating part 13 in an inclined manner, under the action of the inclined inner wall of the casing 1, the sealing part 2 can rebound to a state before deformation after deformation, namely, the sealing part 2 is closely attached to the inner wall of the casing 1, the sealing part 2 is closely attached to the inner wall of the second air hole 15, and the second air hole 15 is blocked from communicating with the interior of the cylindrical battery. It is understood that both ends of the accommodating portion 13 may seal the housing 1 with the sealing member 2 to obtain an explosion-proof effect. In an embodiment, the two ends are respectively provided with the first sealing part 11 and the second sealing part 14, the cathode of the traditional battery is welded with the shell 1, the processing difficulty is high, and the step of leading out the cathode to be welded with the shell 1 can be reduced by adopting the cylindrical battery, so that the processing difficulty is greatly reduced.

Further, the sealing member 2 further comprises a groove 8, the groove 8 surrounds the periphery of the first air hole 12, the sealing member 2 is further provided with a plug portion 72, and the plug portion 72 is connected with the protruding portion 71 and is arranged on the groove 8.

Specifically, the number of the grooves 8 is equal to the number of the first air holes 12, and the grooves are arranged outside the first sealing part 11 and respectively surround the periphery of the first air holes 12. The sealing member plug portion 72 is connected to the sealing member boss 71, and it is understood that the sealing member 2 disposed in the first air hole 12 is a boss, and the sealing member 2 disposed in the groove 8 is a plug portion. The sealing element 2 is additionally provided with the plugging head 72, so that the connection firmness of the sealing element 2 and the shell 1 can be greatly improved, the sealing element 2 is prevented from being separated from the shell 1, and meanwhile, the first sealing part 11 and the plugging head 72 can be connected more smoothly and beautifully by additionally arranging the groove 8 for placing the plugging head 72 of the sealing element.

Further, the number of the plug portions 72 is plural, and a part of the plug portions 72 are connected.

Specifically, the number of the plug portions 72 is equal to that of the first air holes, and the plug portions 72 may be extended so that the connection forms an arc body, and when all the plug portions 72 are connected, a ring body sleeved on the first sealing portion 11 is formed, preferably, part of the plug portions 72 are connected to form a plurality of arc bodies and surround the periphery of the first sealing portion 11.

By forming a plurality of arc bodies around the periphery of the first sealing portion 11 through the connection between the plug portion 72 and the plug portion 72, the connection firmness of the sealing member 2 and the housing 1 can be further improved.

The battery provided by the embodiment of the invention has the following beneficial effects:

firstly, the sealing function and the most important function of the sealing layer isolate the inside and the outside of the battery, and the sealing layer of the battery must have good sealing performance because electrolyte in the battery or the capacitor easily reacts with moisture and oxygen in the air; secondly, explosion-proof effect, because battery or electric capacity are energy storage device, inside a large amount of energy storage, the inside high pressure that can produce of this device when short circuit, and sealed battery is the metal casing, consequently the sealing layer just needs to have explosion-proof pressure release's effect, because traditional explosion-proof valve is expensive, the sealing layer only has the explosion-proof effect on some low-end steel shell batteries. The traditional steel shell cylindrical battery has a complex sealing and explosion-proof structure and is expensive, while the capacitive battery is sealed in the form of a beam waist and a rubber plug, electrolyte is easy to leak at high temperature, and explosion can occur when short circuit occurs. Accordingly, the present application proposes a cylindrical battery with a check valve (i.e., a seal 2) of a self-repairing structure to improve the safety and waterproof properties of the battery.

Referring to fig. 17, the embodiment of the invention further provides a preparation method of the cylindrical battery, which comprises the following steps S1-S4:

s1, preparing a shell, and placing a preset core body in the shell;

specifically, preparing the case includes shaping, which means preparing the battery case into a desired shape.

In one embodiment, the pre-set core is prepared by steps S11-S12:

s11, preparing a pole piece: the positive and negative electrode materials are prepared into active materials and loaded on the current collector, and positive and negative electrode tabs are loaded on the positive and negative electrode plates (when full tabs or multi-tab are adopted, the positive and negative electrode tabs are directly loaded at the cutting positions of the end parts of the current collector without adopting a welding mode).

S12, winding or stacking: the positive pole piece and the negative pole piece are insulated by a diaphragm and then wound into a winding core. Or prepared as a stack in a layer-by-layer stack, in one embodiment, the stack is in a first stacked configuration (anode-separator (solid electrolyte) -cathode-separator (solid electrolyte) -anode … …), or the stack is in a second stacked configuration (cathode-separator (solid electrolyte) -cathode … …).

And placing a preset core body in the shell, welding the core body and the bottom of the shell, welding the tab at the non-sealing end of the winding core with the shell, and then injecting electrolyte into the core body.

Specifically, the battery is isolated from air, and the sealed shell is subjected to an aging process and a formation process treatment by injecting a first liquid packaging material into the shell and waiting for the solidification of the first liquid packaging material to form a sealing element so as to seal the shell for the first time. The aging process is to put the core body injected with the electrolyte into a high-temperature room for aging, so that the electrolyte fully infiltrates the positive and negative pole pieces of the battery. The formation process refers to the first charging process of the lithium battery after the liquid injection. This process can activate the active material in the battery, activating the lithium battery. Meanwhile, the lithium salt and the electrolyte undergo side reaction, a Solid Electrolyte Interface (SEI) film is generated on the negative electrode side of the lithium battery, and the film can prevent the side reaction from further happening, so that the loss of active lithium in the lithium battery is reduced.

In one embodiment, referring to fig. 18, after the battery passes through the formation process, steps S3-S4 are further included:

and S3, exhausting the gas in the cavity formed by the shell and the sealing piece.

Optionally, after the battery generates gas through the formation process and discharges the gas, the sealing member obtained by solidifying the first liquid packaging material is punctured, so that the gas generated by the formation process is discharged from the inside of the shell.

Specifically, a third liquid packaging material is injected above the sealing member formed by solidifying the first liquid packaging material, and a new sealing member is formed by waiting for solidifying the third liquid packaging material, so that the shell is sealed for the second time, and a cylindrical battery with a plurality of layers of sealing members is obtained.

In an embodiment, the core body includes a full tab, and in step S1, a surface of the full tab is coated with a second liquid encapsulation material.

Specifically, the core body comprises a winding core prepared by winding or a stacked core prepared by a lamination method, and the full tab becomes a multipolar tab. The second liquid packaging material is coated on the multi-lug part, after the second liquid packaging material is cured, the lug is subjected to soft leveling process treatment, and the sharp part at the edge of the lug can be effectively prevented from piercing the diaphragm to cause short circuit of the battery in the soft leveling process treatment process because the lug and the diaphragm are wrapped by the second liquid packaging material.

In one embodiment, the circuit board further includes a PCBA circuit board, and after step S2, the circuit board further includes: and injecting a fourth liquid packaging material into the PCBA circuit board, and waiting for the fourth liquid packaging material to be solidified to obtain the sealing piece.

The traditional steel shell battery is characterized in that a protective plate (circuit board) is arranged in a shell, the protective plate is covered by a cover cap, so that the protective plate is packaged on the battery, the cover cap is a protective component covered on the battery and is usually made of plastic or metal materials, and the cost of the battery is directly influenced by the material of the cover cap.

In this embodiment, a layer of seal may be added to encapsulate the PCBA circuit board within the housing. Specifically, after step S2, the PCBA circuit board is placed on the sealing member obtained by the first liquid state solidification, then a fourth liquid state sealing material is injected into the PCBA circuit board, the fourth liquid state sealing material is waited for solidification to obtain a new sealing member, the PCBA circuit board is packaged in the shell through the sealing member obtained by the fourth liquid state sealing material solidification, or after step S4, the PCBA circuit board is placed on the sealing member obtained by the third liquid state solidification, then a fourth liquid state sealing material is injected into the PCBA circuit board, the fourth liquid state sealing material is waited for solidification to obtain a new sealing member, and the PCBA circuit board is packaged in the shell through the sealing member obtained by the fourth liquid state sealing material solidification. The PCBA circuit board refers to a protective plate welded on an electrode, so that overcharge or overdischarge is prevented when a battery is charged, the PCBA circuit board can be specifically determined by referring to the existing data, and the invention is not particularly limited.

The PCBA circuit board is encapsulated in the shell through the sealing piece obtained by solidifying the fourth liquid encapsulating material, and compared with the cap, the sealing piece has sealing property, and the cost corresponding to the cap made of the purchased plastic material and the metal material can be saved.

In the foregoing embodiments, the descriptions of the embodiments are focused on, and for those portions of one embodiment that are not described in detail, reference may be made to the related descriptions of other embodiments.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be attached, detached, or integrated, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms should not be understood as necessarily being directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, one skilled in the art can combine and combine the different embodiments or examples described in this specification.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

While the invention has been described with reference to certain preferred embodiments, it will be understood by those skilled in the art that various changes and substitutions of equivalents may be made and equivalents will be apparent to those skilled in the art without departing from the scope of the invention. Therefore, the protection scope of the invention is subject to the protection scope of the claims.

Claims

1. A cylindrical battery comprising a housing and a seal, the housing comprising a first seal and a first air vent; the first air hole is formed in the first sealing part, the sealing piece is arranged in the first sealing part and made of elastic materials, the sealing piece is provided with a protruding part, and the protruding part is embedded into the first air hole; the shell further comprises a corner collecting part and a containing part, the first sealing part is obliquely connected with the containing part, and the first sealing part is connected with the corner collecting part; the inclination angle between the first sealing part and the accommodating part is 135-179 degrees.

2. The cylindrical battery of claim 1, further comprising a fixture provided with a cushion bladder, the fixture being connected to the seal.

3. The cylindrical battery of claim 2, wherein the housing further comprises a recess connected to the first seal and the receptacle, respectively.

4. The cylindrical battery according to claim 3, wherein the fixing member has a diameter smaller than an inner diameter of the sealing portion, and the fixing member has a diameter smaller than an inner diameter of the recess portion.

5. The cylindrical battery of claim 1, further comprising a core and a first tab, the core being disposed within the housing, the first tab being provided with a snap-fit portion, the first tab passing through the seal and being connected to the core.

6. The cylindrical battery of claim 5, wherein the sealing member has a coefficient of thermal expansion and contraction equal to a coefficient of thermal expansion and contraction of the core.

7. The cylindrical battery of claim 5, further comprising a plurality of sealing members, wherein the core comprises a second tab and a third tab, the housing further comprises a second sealing portion and a second air hole, the first sealing portion and the second sealing portion are respectively connected with the accommodating portion, the second air hole is formed in the second sealing portion, the sealing members are respectively arranged in the first sealing portion and the second sealing portion, the first sealing portion is arranged around the second tab, and the second sealing portion is arranged around the third tab.

8. The cylindrical battery according to claim 7, wherein the second sealing portion is connected obliquely to the receiving portion.

9. The cylindrical battery of claim 1, further comprising a plurality of seals, a plurality of the seals being stacked within the first seal portion.

10. The cylindrical battery of claim 9, wherein the first air holes are arranged around the periphery of the first sealing portion and are provided in a plurality of rows.

11. The cylindrical battery of claim 1, further comprising a groove surrounding the first air hole, wherein the sealing member is further provided with a blocking head connected to the protruding portion and disposed on the groove.

12. The cylindrical battery according to claim 11, wherein the number of plug portions is plural, and a part of the plug portions are connected.

13. The cylindrical battery of claim 1, wherein the seal has a thickness of less than or equal to 1mm.

14. The cylindrical battery of claim 1, further comprising a first identifier and a second identifier, wherein the first identifier and the second identifier are both disposed on the seal.

15. A method of preparing a cylindrical battery as claimed in any one of claims 1 to 14, comprising:

s1, preparing a shell, and placing a preset core body in the shell;

16. The method of claim 15, wherein the core comprises a full tab, and the surface of the full tab is coated with a second liquid encapsulation material in step S1.

17. The method of claim 15, further comprising, after step S2:

s3, exhausting the gas in the cavity formed by the shell and the sealing piece;