CN113346201A

CN113346201A - Cylindrical battery, battery module and battery pack

Info

Publication number: CN113346201A
Application number: CN202110559601.6A
Authority: CN
Inventors: 黄利明; 岳亮亮; 刘静; 徐悦斌; 何巍
Original assignee: Eve Power Co Ltd
Current assignee: Eve Power Co Ltd
Priority date: 2021-05-21
Filing date: 2021-05-21
Publication date: 2021-09-03

Abstract

The invention relates to a cylindrical battery, comprising a casing, a battery core, a pole column, a cover plate, a positive electrode current collecting plate and a negative electrode current collecting plate. The current collecting discs are all arranged inside the casing. The cover plate is connected with the notch of the casing. The pole is riveted with the casing, the pole penetrates into the interior of the casing through the bottom end face of the casing, and an insulating seal is arranged between the pole and the casing. The battery cell is an all-pole lug structure. The two end faces of the battery cell are respectively connected with the positive electrode current collector plate and the negative electrode current collector plate. The collector plate is electrically connected. The present invention also relates to a battery module comprising the above-mentioned cylindrical battery. The present invention also relates to a battery pack comprising the above-mentioned battery module.

Description

Cylindrical battery, battery module and battery pack

Technical Field

The invention relates to the field of batteries, in particular to a cylindrical battery, a battery module and a battery pack.

Background

The existing cylindrical lithium ion battery generally comprises a shell, a battery cell, electrolyte and a cap, wherein the battery cell, the electrolyte and the cap are accommodated in the shell. The shell is generally a cylindrical groove body made of metal materials, the cap is connected with the notch of the shell, and the cap and the shell are insulated and sealed by a sealing rubber ring, so that the integrity and the tightness of the shell are kept. The battery cell is generally formed by winding a positive plate, a negative plate and a diaphragm, the positive plate and the negative plate are respectively provided with a positive electrode lug and a negative electrode lug which are perpendicular to the pole pieces, the battery cell is connected with a cover cap through the positive electrode lug, therefore, the cover cap is also used as a positive connecting terminal, and the battery cell is connected with the shell through the negative electrode lug, so that the shell is negatively charged. The cover cap is provided with a liquid injection hole and an explosion-proof valve, so that the cover cap simultaneously plays the roles of the positive connecting terminal, the sealing piece and the explosion-proof piece.

Before the conventional cylindrical lithium ion battery is subjected to PACK, the side wall of the shell is subjected to insulation treatment, and at the moment, the anode connecting terminal and the cathode connecting terminal of the cylindrical lithium ion battery can be respectively arranged on two end faces of the cylindrical lithium ion battery. Therefore, the existing cylindrical lithium ion battery has the technical problems that:

1. the positive connecting terminal and the negative connecting terminal are respectively arranged on two end faces of the cylindrical lithium ion battery, and certain limitation is imposed on the battery grouping technology. When the batteries are connected in series and in parallel to form a group, the batteries must be placed according to the requirements of the polarities of the corresponding positions, so that the risks of pre-positioning and placing errors are increased;

2. the positive connecting terminal and the negative connecting terminal are respectively arranged on two end faces of the cylindrical lithium ion battery, so that the grouped cooling area of the battery can only be arranged on the outer side wall of the battery, the contact area of the cooling pipe and the battery is limited, and the space utilization rate of a battery module in the horizontal direction is reduced;

3. a steel ladle for welding is generally required to be additionally arranged on the surface of an explosion-proof valve of a cover cap adopted by the battery, so that the battery is influenced to be opened under extreme conditions to release internal energy;

4. the cap and the shell of the battery are insulated and sealed by adopting the sealing rubber ring, and when the battery is discharged at a large multiplying power, the heat release of the positive electrode can be conducted only through the external connecting sheet and the internal lug, so that the heat diffusion efficiency is low, the problem of local overheating is easy to occur, and the thermal runaway of the battery is caused;

5. the positive pole and the negative pole of the battery cell respectively lead out the positive pole current and the negative pole current in the battery cell through the positive pole lug and the negative pole lug, and then are connected with the positive pole connecting terminal and the negative pole connecting terminal through the positive pole lug and the negative pole lug. Thus, the positive and negative electrode tabs generate a large amount of heat during high-rate discharge, and thermal runaway is likely to occur even if local heat generation is too large.

Disclosure of Invention

In view of the technical problems in the prior art, in one aspect, the present invention provides a cylindrical battery, in which a positive connection terminal and a negative connection terminal of the cylindrical battery may be disposed at the same end surface of the cylindrical battery.

In order to achieve the purpose, the invention adopts the following technical scheme: a cylindrical battery comprises a shell, an electric core, a pole column, a cover plate, a positive current collecting plate, a negative current collecting plate and an insulating sealing element. The shell is of a cylindrical groove body structure, and the battery cell, the anode current collecting disc and the cathode current collecting disc are all arranged inside the shell. An electrolyte solution is also disposed inside the case to enable the battery to be charged and discharged through electrochemical reactions of the positive electrode, the negative electrode, and the electrolyte solution of the cell. The electrolyte solution may be composed of organic solvents such as EC, PC, DEC, EMC and organic solvents such as LiPF₆Or LiBF₄The lithium salt of (1). The electrolyte solution may be in a liquid, solid or gel state.

The housing is made of a material that may be a conductive metal or an insulating material.

In one embodiment, when the casing is made of an insulating material, the cover plate is electrically connected to the negative current collecting plate, the terminal is electrically connected to the positive current collecting plate, the terminal and the cover plate are respectively used as a positive connecting terminal and a negative connecting terminal of the cylindrical battery, and the positive connecting terminal and the negative connecting terminal are respectively arranged on two end faces of the cylindrical battery.

In one embodiment, when the case is made of a conductive metal material, the case is electrically connected with the negative current collecting plate so as to be negatively charged, and the pole column is electrically connected with the positive current collecting plate so as to be positively charged.

In one embodiment, when the case is made of a conductive metal material, the case is electrically connected with the positive current collecting plate so as to be positively charged, and the pole is electrically connected with the negative current collecting plate so as to be negatively charged.

For convenience of description, the end surface of the housing where the notch is located is referred to as a "tip end surface". The end surface of the housing remote from the slot is referred to as the "bottom end surface".

The battery core is formed by winding a positive plate, a negative plate and a diaphragm which are stacked, the battery core adopts a full lug or die-cutting lug flattening process, the positive end of the battery core and the positive current collecting disc are connected through laser end face welding, the negative end of the battery core and the negative current collecting disc are connected through laser end face welding, and the current collecting efficiency of the battery can be improved and the internal resistance of the battery can be greatly reduced by arranging the positive current collecting disc and the negative current collecting disc.

Utmost point post and casing riveting, utmost point post run through the inside that gets into the casing by the bottom face of casing. Be provided with insulating seal between utmost point post and the casing, insulating seal can realize sealing the position that utmost point post runs through the casing, and insulating seal can prevent utmost point post and casing contact simultaneously.

The part of the pole column positioned in the shell can be connected with the positive current collecting plate and can also be connected with the negative current collecting plate.

When the polar column is connected with the positive current collecting disc, one end of the polar column, which is positioned inside the shell, is electrically connected with the positive electrode end of the battery cell through the positive current collecting disc, and one end of the polar column, which is positioned outside the shell, is used as a positive connecting terminal of the battery. The positive current collecting disc is not contacted with the shell, and a fuse is arranged at the connecting part of the positive current collecting disc and the pole.

When the pole is connected with the negative current collecting disc, one end of the pole, which is positioned inside the shell, is electrically connected with the negative end of the battery cell through the negative current collecting disc, and one end of the pole, which is positioned outside the shell, is used as a negative connecting terminal of the battery.

The cover plate is connected with the notch of the shell, the cover plate covers the top end face of the shell or the notch of the shell, the explosion-proof valve is arranged on the cover plate, and the cover plate plays roles of a sealing piece and an explosion-proof piece at the same time.

In one embodiment, the cover plate and the housing are insulated and sealed by a sealing rubber ring, the pole is connected with the positive current collecting disc, the cover plate is electrically connected with the negative current collecting disc, and the cover plate can be used as a negative connecting terminal.

In one embodiment, a sealing rubber ring is adopted between the cover plate and the shell for insulation and sealing, and the cover plate is not in contact with the anode current collecting disc, so that the cover plate only plays the roles of a sealing piece and an explosion-proof piece.

In one embodiment, the cover plate and the housing are welded by laser, and the cover plate is electrically connected with the anode current collecting plate, so that the cover plate can be used as the anode connecting terminal.

In one embodiment, the cover plate is further provided with a liquid injection hole, the liquid injection hole penetrates through the cover plate, after the cover plate is connected with the shell, electrolyte solution is injected into the shell through the liquid injection hole in the cover plate, and after liquid injection is completed, the sealing piece and the cover plate are connected through laser welding to seal the liquid injection hole.

Compared with the prior art, the cylindrical battery provided by the invention has at least the following beneficial effects:

1. the pole posts are integrated on the bottom end surface of the shell, so that the cylindrical batteries can be welded in series and parallel connection from the same end surface when being grouped, and the orientation of the pole posts can be the same when a plurality of batteries are placed in groups;

2. the positive current collecting disc and the negative current collecting disc are adopted for collecting current, so that an electronic transmission channel from a battery cell to a positive connecting terminal and a negative connecting terminal is improved, and the problem of heating of a lug during high-magnification work is solved;

3. the fuse design is carried out on the positive current collecting disc, when the battery is charged and discharged extremely, the temperature of the connecting part of the positive current collecting disc and the pole column rises to exceed a threshold value, so that the fuse is fused, an open circuit is formed inside the battery, and the thermal runaway of the battery is prevented;

4. through the connected mode of control apron and casing, can realize one in following beneficial effect: a. the utilization rate of the inner space of the shell is increased; b. the negative electrode conduction efficiency of the battery is increased; c. the cover plate is not charged as a seal.

In a second aspect, the present invention provides a battery module, which includes the cylindrical battery.

In a third aspect, the invention provides a battery pack, which includes the above battery module, and the battery pack can be applied to electric vehicles, energy storage devices, and electric devices.

Drawings

The figures further illustrate the invention, but the examples in the figures do not constitute any limitation of the invention.

Fig. 1 is a front view of a cylindrical battery provided in embodiment 1 of the present invention.

Fig. 2 is a sectional view of a portion a of fig. 1.

Fig. 3 is a sectional view of part B of fig. 1.

Fig. 4 is a front view of a cylindrical battery provided in embodiment 2 of the present invention.

Fig. 5 is a sectional view of part C of fig. 4.

Fig. 6 is a sectional view of a portion D of fig. 4.

Fig. 7 is a front view of a cylindrical battery provided in example 3 of the present invention.

Fig. 8 is a sectional view of a portion E of fig. 7.

Fig. 9 is a cross-sectional view of a portion F of fig. 7.

Wherein the reference numerals are: 1. a housing; 2. an electric core; 3. a pole column; 4. a cover plate; 5. a positive current collector; 6. a negative current collecting plate; 7. an insulating seal; 8. sealing the rubber ring; 9. a rigid connection.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the present invention, it is to 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", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; they may be mechanically coupled, directly coupled, or indirectly coupled through intervening agents, both internally and/or in any other manner known to those skilled in the art. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly above and obliquely above the second feature, or simply meaning that the first feature is at a lesser level than the second feature.

The cover plates described in examples 1 to 3 were each provided with an explosion-proof diaphragm and a liquid inlet.

The battery cell described in embodiments 1 to 3 includes a positive electrode tab, a negative electrode tab, and a separator, which are stacked; the cells described in examples 1 to 3 were all full-tab cells prepared by winding; the cells described in examples 1 to 3 were of a column-shaped structure, and both end faces (i.e., the positive electrode terminal and the negative electrode terminal) were welded to the end faces of the positive current collecting plate and the negative current collecting plate, respectively.

In examples 1 to 3, in order to reduce the overall height of the cylindrical battery and make the cylindrical battery meet the national standard, the end surfaces of the poles located inside the case in examples 1 to 3 are provided with a groove, the end surfaces of the positive current collecting plates far away from the battery core in examples 1 to 3 are provided with protrusions, the width of the protrusions is smaller than that of the grooves, the protrusions enter the grooves and are welded to the bottom surfaces of the grooves, and the protrusions are provided with fuses. In examples 1-3, the connection part of the post and the positive current collecting plate was only: the end surface of the protrusion far away from the battery core is connected with the bottom surface of the groove.

In examples 1 to 3, the terminal post and the housing were both riveted, and the terminal post was disposed on the bottom end surface of the housing.

Example 1

As shown in fig. 1 to 3, the present embodiment provides a cylindrical battery, which includes a casing 1, a battery core 2, a terminal 3, a cover plate 4, a positive current collecting plate 5, a negative current collecting plate 6, and an insulating sealing member 7. The casing 1 is a cylindrical tank body structure, the battery cell 2, the anode current collecting disc 5 and the cathode current collecting disc 6 are all arranged inside the casing 1, and the battery cell 2, the electrolyte, the anode current collecting disc 5 and the cathode current collecting disc 6 are arranged inside the casing 1.

The cover plate 4 is connected with the notch of the casing 1, and the connection structure of the cover plate 4 and the casing 1 is the same as the connection structure of the cap disclosed in the existing chinese patent CN200620014774.0 (cylindrical lithium battery combined cap and battery) and the casing of the cylindrical lithium ion battery, but in this embodiment, there is no sealing rubber ring between the cover plate 4 and the casing 1, so that in order to further realize the sealing connection of the cover plate 4 and the casing 1, the connection part of the casing 1 and the cover plate 4 are welded and connected by laser welding, thereby realizing the sealing of the casing 1.

Utmost point post 3 sets up the terminal surface of keeping away from the notch at casing 1, and

utmost point post

3 and 1 riveting of casing, and insulating seal 7 is filled between utmost point post 3 and casing 1 simultaneously to make utmost point post 3 not contact with casing 1, insulating seal 7 is isolated with anodal current collector 5 and casing 1 simultaneously also, thereby makes anodal current collector 5 not contact with casing 1.

Electric core 2 is the electric core of full utmost point ear structure, and electric core 2 is through convoluteing the preparation, and electric core 2 includes positive pole piece, negative pole piece and diaphragm, and the specific structure of electric core 2 is the same with the structure of the full utmost point ear electric core of coiling preparation disclosed among the prior art, therefore does not give unnecessary details here. The positive end of the electric core 2 is connected with the positive current collecting disc 5 through end face welding, and the negative end of the electric core 2 is connected with the negative current collecting disc 6 through end face welding. The positive current collector 5, the cell 2 and the negative current collector 6 form a stack, which also serves as a mechanical protection for the cell 2.

Before the casing 1 and the cover plate 4 are connected, the casing 1 needs to be subjected to roll groove forming, so that an inwards concave necking is formed on the part, close to the notch, of the casing 1, the necking can extrude the negative current collecting plate 6, and therefore the positive current collecting plate 5, the battery core 2 and the negative current collecting plate 6 form a laminated structure and are clamped between the necking of the casing 1 and the groove bottom surface inside the casing 1, and the insulating sealing member 7 is filled between the positive current collecting plate 5 and the groove bottom surface inside the casing 1.

The part of the pole 3 positioned in the shell 1 is connected with the positive current collecting plate 5 in a welding way. The portion of the post 3 located outside the case 1 may serve as a positive connection terminal.

In this embodiment, anode current collecting plate 6 is electrically connected to cover plate 4, and case 1 is in contact with anode current collecting plate 6 and cover plate 4, so that case 1 is negatively charged. Either the lid plate 4 or the case 1 may serve as the negative connection terminal. When the cylindrical battery provided by this embodiment is packed (packaged or encapsulated) to form a battery module, the outer sidewall of the casing 1 and the cover plate 4 can be coated with insulating plastic, and at this time, the positive connection terminal and the negative connection terminal of the cylindrical battery are both disposed on the bottom end surface of the casing 1.

Example 2

As shown in fig. 4-6, the present embodiment provides a cylindrical battery, which includes a casing 1, a battery core 2, a terminal 3, a cover plate 4, a positive current collecting plate 5, a negative current collecting plate 6, an insulating sealing member 7, and a sealing rubber ring 8. The differences between the cylindrical battery provided in this embodiment and the cylindrical battery provided in embodiment 1 at least include: the cylinder type battery that this embodiment provided, the notch of apron 4 and casing 1 is connected, through sealed rubber ring 8 sealed fixed connection between the periphery of apron 4 and the casing 1, the periphery of sealed rubber ring 8 cladding apron 4, casing 1 is sealed with sealed rubber ring 8 and apron 4 compaction by the inside pressfitting of 8 surface outside sealed rubber ring, and the part of sealing only has apron, sealed rubber ring 8 and casing to participate in.

The cylindrical battery provided by the embodiment has a firm structure and good sealing performance, the anode current collecting plate 6 is not connected with the cover plate 4, the cover plate 4 is not electrified, and the shell 1 and the anode current collecting plate 6 are in contact connection to serve as an anode connecting terminal.

Example 3

As shown in fig. 7-9, the present embodiment provides a cylindrical battery, which includes a casing 1, a battery core 2, a terminal 3, a cover plate 4, a positive current collecting plate 5, a negative current collecting plate 6, an insulating sealing member 7, and a rigid connecting member 9.

The differences between the cylindrical battery provided in this embodiment and the cylindrical battery provided in embodiment 1 at least include: in the cylindrical battery provided in the present embodiment, the notch of the case 1 and the end surface of the lid plate 4 facing the case 1 are laser welded. The diameter of the cover plate 4 in the horizontal direction is equal to the maximum diameter of the casing 1, and the end face of the cover plate 4 located inside the casing 1 is rigidly connected to the anode current collecting plate 6, that is, the cover plate 4 supports the anode current collecting plate 6 through the rigid connector 9, that is, the cover plate 4 fixedly supports the battery cell inside the casing 1 through the rigid connector 9. In this embodiment, rigid connector 9 and anode current collecting plate 6 are integrally connected, and rigid connector 9 and end surface of cover plate 4 located inside case 1 are connected by laser welding.

In this embodiment, the anode current collecting plate 6 and the cover plate 4 are electrically connected by the rigid connector 9, and the case 1 and the cover plate 4 are electrically connected, so that the case 1 is negatively charged. Either the lid plate 4 or the case 1 may serve as the negative connection terminal. When the cylindrical battery provided by this embodiment is packed (packaged or encapsulated) to form a battery module, the outer sidewall of the casing 1 and the cover plate 4 can be coated with insulating plastic, and at this time, the positive connection terminal and the negative connection terminal of the cylindrical battery are both disposed on the bottom end surface of the casing 1.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A cylindrical battery, comprising a casing, an electric core, a pole, a cover plate, a positive electrode current collector plate, and a negative electrode current collector plate, the casing is a cylindrical groove structure, the battery core, the positive electrode The current collecting plate and the negative electrode current collecting plate are both arranged inside the casing, and are characterized in that:

the cover plate is connected with the notch of the casing;

The pole and the casing are riveted, the pole penetrates into the interior of the casing from the bottom end face of the casing, and an insulating seal is arranged between the pole and the casing;

The two end faces of the battery cell are respectively connected with the positive electrode current collecting disk and the negative electrode current collecting disk, and one end of the pole column located inside the casing passes through the positive electrode current collecting disk or the negative electrode current collecting disk and the negative electrode current collecting disk. The battery cell is electrically connected, and the casing is electrically connected to the positive electrode current collecting plate or the negative electrode current collecting plate.

2 . The cylindrical battery according to claim 1 , wherein one end of the pole located inside the casing is connected to the positive current collector plate, and the pole located on the end surface inside the casing is provided. 3 . There is a groove, the end face of the positive current collecting plate away from the battery core is provided with a protrusion, the width of the protrusion is smaller than the width of the groove, the protrusion enters the groove and communicates with the groove. The groove bottom surfaces of the grooves are connected, and the protrusions are provided with fuses.

3 . The cylindrical battery according to claim 2 , wherein an explosion-proof valve is provided on the cover plate. 4 .

4 . The cylindrical battery according to claim 3 , wherein the cover plate is provided with a liquid injection hole, and the liquid injection hole penetrates the cover plate. 5 .

5 . The cylindrical battery according to claim 4 , wherein a sealing rubber ring is used for insulation and sealing between the cover plate and the casing, and the cover plate and the negative electrode current collector are electrically conductive. 6 . connect.

6 . The cylindrical battery according to claim 4 , wherein a sealing rubber ring is used for insulation and sealing between the cover plate and the casing, and the cover plate and the negative electrode current collecting plate are not in contact. 7 .

7 . The cylindrical battery according to claim 4 , wherein the cover plate covers the notch of the casing, and laser welding is used between the cover plate and the casing, and the cover plate and the casing are welded. 8 . The negative electrode current collecting plate is electrically connected.

8 . The cylindrical battery according to claim 4 , wherein the cover plate covers the top surface of the casing, and laser welding is used between the cover plate and the casing, and the cover plate and the casing are welded. The negative electrode current collector discs are rigidly connected.

9. A battery module, characterized in that it comprises the cylindrical battery according to any one of claims 1-8.

10. A battery pack, comprising the battery module of claim 9.