CN109004261B

CN109004261B - Battery cell

Info

Publication number: CN109004261B
Application number: CN201810731374.9A
Authority: CN
Inventors: 王生义; 姬国庆
Original assignee: Guangdong Mic Power New Energy Co Ltd
Current assignee: Guangdong Mic Power New Energy Co Ltd
Priority date: 2018-07-05
Filing date: 2018-07-05
Publication date: 2024-07-30
Anticipated expiration: 2038-07-05
Also published as: CN109004261A

Abstract

The invention discloses a battery. The battery comprises a battery core, wherein the battery core comprises a pole piece unit and a core column, the pole piece unit is wound on the outer side of the core column, the core column comprises at least one electric connection part, the electric connection part comprises an elastic element, a main body part and a conductor part positioned at one end of the main body part, the elastic element is configured to form pre-elastic force on the conductor part so that the conductor part is abutted to equipment outside the battery core, and a current collector positioned on the inner side of the pole piece unit is connected with the core column and is communicated with the conductor part.

Description

Battery cell

Technical Field

The invention relates to the technical field of energy storage equipment, in particular to a battery.

Background

Some batteries, particularly lithium ion batteries, generally include a housing, a cap, and a cell. The battery cell is positioned in the inner cavity of the shell and is insulated from the shell. The cap is capped at the open end of the housing. The battery cell is manufactured by a pole piece unit in a winding mode. The pole piece unit comprises a positive pole piece, a diaphragm and a negative pole piece which are attached together. And the current collector of the positive plate is welded with the cap. The cap forms the positive electrode of the battery. The current collector of the negative plate is welded with the shell. The bottom of the case serves as the negative electrode of the battery.

However, some miniature batteries have a small size, a maximum size of usually less than 10mm, and a low structural strength of the pole piece unit, so that it is difficult for the pole piece unit to form a rolled structure of a set shape when winding is performed, and the yield of the battery is reduced.

In addition, the shell and the cap of the miniature battery are small, so that the working space is limited when the current collector is welded, and the current collector is difficult to weld in place.

Therefore, a new technical solution is needed to solve the above technical problems.

Disclosure of Invention

It is an object of the present invention to provide a new solution for a battery.

According to a first aspect of the present invention, a battery is provided. The battery comprises a battery core, wherein the battery core comprises a pole piece unit and a core column, the pole piece unit is wound on the outer side of the core column, the core column comprises at least one electric connection part, the electric connection part comprises an elastic element, a main body part and a conductor part positioned at one end of the main body part, the elastic element is configured to form pre-elastic force on the conductor part so that the conductor part is abutted to equipment outside the battery core, and a current collector positioned on the inner side of the pole piece unit is connected with the core column and is communicated with the conductor part.

Optionally, the main body portion includes a tubular portion, the elastic element and the conductor portion are both located in an inner cavity of the tubular portion, an opening end of the tubular portion is provided with a stop portion for preventing the conductor portion from falling off, one end of the elastic element abuts against the main body portion or other portions of the stem, and the other end abuts against the conductor portion.

Optionally, the cylindrical portion includes a conductor layer and an insulating layer covering the conductor layer, a through hole is formed in a side wall of the cylindrical portion, the current collector passes through the through hole and is conducted with the conductor layer, and the conductor layer is conducted with the conductor portion.

Optionally, the current collector is connected to the conductor layer by soldering or conductive glue.

Optionally, the electrical core includes an insulating portion and two electrical connection portions located at two ends of the insulating portion in an axial direction, and conductor portions of the two electrical connection portions are located at one ends of the main body portions, which are far away from the insulating portion, respectively.

Optionally, the core column and the two support plates are connected together to form an I-shaped structure, and the pole piece unit is located between the two support plates.

Optionally, a notch is provided in at least one of the support plates, the notch being configured for one of the current collectors to protrude from within the i-shaped structure.

Optionally, the support plate is detachably connected with the stem.

Optionally, the battery further includes a housing, the housing includes a first housing and a second housing, each of the first housing and the second housing includes a straight cylinder and a bottom located at one end of the straight cylinder, the first housing and the second housing are inserted, the straight cylinder of the first housing is located at the outer side of the straight cylinder of the second housing, a containing cavity is formed between the first housing and the second housing, the battery cell is located in the containing cavity, and the two bottoms respectively abut against the two conductor parts; or alternatively

And through holes are formed in the parts of the two bottom parts corresponding to the respective conductor parts so that the conductor parts can penetrate out of the through holes, and the two conductor parts respectively serve as a positive electrode and a negative electrode of the battery.

Optionally, the positions of the straight cylinder body of the first shell and the straight cylinder body of the second shell corresponding to each other are provided with protruding portions and/or recessed portions, so that the first shell and the second shell are clamped.

According to one embodiment of the present disclosure, the cell includes a stem. The pole piece units are wound outside the core column. The stem provides structural support for the winding process of the pole piece units. When winding, one current collector of the pole piece unit is fixed on the core column and wound around the core column in a lamination way. In this way winding of the pole piece units is easier.

Further, due to the presence of the stem, the pole piece unit can be effectively braced at the time of winding, so that it can be firmly wound on the stem and can be prevented from being deflected at the time of winding.

Further, due to the arrangement of the core legs, the winding cores of the same diameter are made longer in the length of the pole piece units wound into, thereby making the capacity of the battery larger.

The current collector is connected to the stem and is electrically connected to an external circuit or the case via an electrical connection. Compared with welding the current collector on the shell or the cap, the current collector is not required to be operated in a narrow space, so that the current collector is easier to connect, and the yield is improved.

In addition, the stem is suitable for the manufacture of smaller batteries, for example, the width of the pole piece units can reach below 10 mm. The thickness of the winding core formed by winding can reach below 2mm.

Other features of the present invention and its advantages will become apparent from the following detailed description of exemplary embodiments of the invention, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a schematic view of an i-shaped structure according to one embodiment of the invention.

Fig. 2 is an assembly view of a cell according to one embodiment of the invention.

Fig. 3 is a cross-sectional view of a cell according to one embodiment of the invention.

Fig. 4 is a cross-sectional view of a battery according to one embodiment of the present invention.

Fig. 5 is a cross-sectional view of the first housing or the second housing according to one embodiment of the present invention.

Fig. 6 is a top view of a cell according to one embodiment of the invention.

Fig. 7 is a top view of another cell according to one embodiment of the invention.

Fig. 8 is a schematic diagram of another i-shaped structure according to one embodiment of the invention.

Fig. 9 is an exploded view of a battery according to an embodiment of the present invention.

Reference numerals illustrate:

11: a conductor section; 12: a support plate; 13: a through hole; 14: a stem; 16: an electrical connection; 17: a cylindrical portion; 18: a spring; 19: pole piece units; 20: a positive electrode current collector; 21: a negative electrode current collector; 22: a first housing; 23: a second housing; 24: a straight cylinder; 25: a bottom; 26: an insulating part; 27: an insulating film; 28: a recessed portion; 29: an open end; 30: a notch; 31: and (3) sealing rings.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise.

The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of exemplary embodiments may have different values.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

According to one embodiment of the present invention, a battery is provided. As shown in fig. 1-3, the battery includes a cell. The battery cell is used for storing electric energy. The cell comprises a pole piece unit 19 and a stem 14. The pole piece units 19 are sheet-like structures that can be wound to form a winding core. The stem 14 has a columnar structure and a predetermined structural strength.

The pole piece unit 19 is wound on the outside of the stem 14. The stem 14 includes at least one electrical connection 16. The electrical connection 16 is used to conduct one pole piece of the pole piece unit 19 to an external circuit or housing. The electrical connection portion 16 includes an elastic element, a main body portion, and a conductor portion 11 located at one end of the main body portion. The elastic member is configured to form a pre-elastic force to the conductor portion 11 so that the conductor portion 11 abuts against a device other than the battery cell, such as a case of a battery, a cap, or an external device. One of the current collectors of the pole piece unit 19 located on the inner side is connected to the stem 14 and is in conduction with the conductor portion 11.

Specifically, the elastic element is a shrapnel, a spring 18, an elastic rubber member, or the like. The elastic element provides elastic force. The body portion is used to form the overall structure of the stem 14. For example, the body portion has a cylindrical structure. Preferably, the main body and the conductor 11 are both conductors, for example, a metal material such as stainless steel, copper alloy, aluminum alloy, or a non-metal material such as graphite, conductive glass, conductive plastic, conductive ceramic, or the like. In this way, the conductor portion 11 and the main body portion can be made conductive. The current collector located on the inner side means the current collector near the center of the pole piece unit 19 after winding. For example, the current collector is located at the beginning of the pole piece unit 19, i.e. the beginning at the time of winding.

In an embodiment of the invention, the cell includes a stem 14. The pole piece unit 19 is wound outside the stem 14. The stem 14 provides structural support for the winding process of the pole piece unit 19. When winding, one current collector of the pole piece unit 19 is fixed to the stem 14 and wound around the stem 14 in a stacked manner. In this way winding of the pole piece units 19 is easier.

Further, due to the presence of the stem 14, the pole piece unit 19 can be effectively braced at the time of winding, so that it can be firmly wound on the stem 14 and can be prevented from being deflected at the time of winding.

Furthermore, due to the arrangement of the stem 14, the winding cores of the same diameter are made longer by the length of the pole piece units 19 wound into, thereby making the capacity of the battery larger.

The current collector is connected to the stem 14 and is electrically connected to an external circuit or housing via an electrical connection 16. Compared with welding the current collector on the shell or the cap, the current collector is not required to be operated in a narrow space, so that the current collector is easier to connect, and the yield is improved.

The stem 14 is suitable for use in the production of smaller batteries, and the width of the pole piece units 19 can be 10mm or less, for example. The thickness of the winding core formed by winding can reach below 2 mm.

In one example, as shown in fig. 1-3, the cell includes an insulating portion 26 and two electrical connections 16 at both ends of the insulating portion 26 in the axial direction. The axial direction is the direction of extension of the body of the cell, as indicated by the arrow a in fig. 1. The conductor portions 11 of the two electrical connection portions 16 are located at the ends of the respective body portions remote from the insulating portion 26. The insulating portion 26 is made of an insulating material such as plastic, rubber, ceramic, glass, or silica gel. Thus, the positive electrode current collector 20 and the negative electrode current collector 21 of the pole piece unit 19 are respectively in one-to-one correspondence with the two electrical connection portions 16, and are respectively conducted to the housing, the cap, or the external circuit through the respective conductor portions 11.

In winding, first, the positive electrode current collector 20 and the negative electrode current collector 21 are connected to the respective stem 14; then, winding is performed again. The two current collectors do not need to be welded with the shell or the cap, so that the processing difficulty is greatly reduced.

In one example, as shown in fig. 3, the body portion includes a cylindrical portion 17. For example, the cross section of the cylindrical portion 17 is circular, square, elliptical, or the like. The elastic element and the conductor part 11 are both located in the inner cavity of the cylindrical part 17. The open end of the cylindrical portion 17 is provided with a stopper portion for preventing the conductor portion 11 from falling off. For example, the stopper is a blocking wall formed by bending an edge of the open end inward or a boss formed by projecting an edge of the open end inward.

One end of the elastic element abuts against the body portion or other portion of the stem 14, and the other end abuts against the conductor portion 11. For example, the elastic element is a spring 18. The cylindrical portion 17 further includes a bottom wall provided at one end. One end of the spring 18 is fixed in the cylindrical portion 17 or directly abuts against the bottom wall; the cylindrical portion 17 may not be provided with a bottom wall, and the spring 18 may directly abut against the insulating portion 26, and may be selected by those skilled in the art according to actual practice.

Preferably, the cell further includes support plates 12 disposed at both ends of the stem 14. The stem 14 and the two support plates 12 are connected together to form an i-shaped structure. The pole piece unit 19 is located between the two support plates 12. The support plate 12 is made of plastic, metal, or the like. The support plate 12 and the stem 14 are insulated from each other.

Preferably, the support plate 12 is made of a composite material. For example, the intermediate frame is made of metal, ceramic, or the like. The outer part is made of materials such as plastic, rubber, silica gel and the like. The support plate 12 is formed by insert molding.

Alternatively, the support plate 12 may be circular, semi-circular, square, oval, or other shape overall. Those skilled in the art can make the settings according to actual needs.

In this example, the two support plates 12 can effectively define the position of the pole piece unit 19, and can further prevent the pole piece unit 19 from sounding deflection upon winding.

In addition, the support plate 12 can protect the end of the winding core from damage when assembled into the housing.

In one example, as shown in fig. 6 and 8, a notch 30 is provided in at least one support plate 12. The notch 30 is configured for one of the current collectors to protrude from within the i-shaped structure. For example, in the case where one current collector is connected to the stem 14 and the other current collector is welded to the case, the notch 30 can effectively avoid the current collector, making the welding of the current collector easy.

In another example, as shown in fig. 7, the support plate 12 has a semicircular structure. In this way the support plate 12 can also function to define the position of the pole piece unit 19.

Furthermore, no notches 30 need be provided for extension of the current collector. The current collector may directly protrude from a portion where the support plate 12 is not provided.

In one example, the support plate 12 is removably connected to the stem 14. For example, the middle of the support plate 12 is provided with a hole. The end of the stem 14 is snapped into the hole. The conductor portion 11 protrudes outward from the support plate 12 or is located below the outer side surface of the support plate 12. The support plate 12 is mounted to the stem 14 while winding is performed. In assembly, the support plate 12 is removed and the cells are mounted in the housing. In this way, the space occupied by the support plate 12 can be effectively saved, interference with the housing is prevented, and the miniaturization design of the battery is facilitated.

In one example, the cylindrical portion 17 includes a conductor layer and an insulating layer covering the conductor layer. The conductor layer is used for conduction between the current collector and the conductor portion 11. The insulating layer is used for insulating the conductor layer from the polar plate unit. For example, the conductor layer is made of a metal material such as stainless steel, copper alloy, or aluminum alloy. The insulating layer is made of plastic, rubber or silica gel and the like which are injection molded on the outer surface of the conductor layer; the insulating layer may be an insulating varnish applied to the outer surface of the conductor layer.

As shown in fig. 1, a through hole 13 is formed in the side wall of the cylindrical portion 17. The current collector passes through the through hole 13 and is in communication with the conductor layer. The conductor layer is in conduction with the conductor portion 11. The shape of the through hole 13 can be set by those skilled in the art according to actual needs.

The current collector is connected to the conductor layer, for example, by welding or conductive glue or the like. The connection mode is easy to operate and high in connection speed.

In this example, the stem 14 includes a conductor layer and an insulating layer, and is capable of performing both conduction and insulation with the pole piece unit 19, without providing a conduction element for conducting the current collector and the conductor portion 11 additionally, simplifying the structure of the stem 14, and the connection structure.

In other examples, the body portion includes an insulating portion 26, two elastic elements, two conductor portions 11, and an integrally provided cylindrical portion 17. The insulating portion 26 is located in the middle of the inner cavity of the cylindrical portion 17. The two elastic elements are springs 18 and are located on either side of the insulating portion 26. The conductor portion 11 slides along the lumen. Stop portions are provided at both ends of the cylindrical portion 17. One end of each of the two springs 18 abuts against the insulating portion 26, and the other end abuts against the conductor portion 11, so that the conductor portion 11 forms an outward pre-elastic force. In this example, the cylindrical portion 17 has a simple structure, and facilitates assembly and processing of the stem 14.

Further, the integrally provided cylindrical portion 17 makes the structural strength of the stem 14 higher.

Similarly, the cylindrical portion 17 is provided with a through hole 13 to facilitate connection of the current collector. The cylindrical portion 17 is made of a composite material to facilitate conduction and insulation.

In one example, as shown in fig. 4, 5 and 9, the battery further includes a housing. The housing comprises a first housing 22 and a second housing 23. The first casing 22 and the second casing 23 are insulated from each other, for example, with an insulating film 27 provided therebetween. As shown in fig. 5, the first housing 22 and the second housing 23 each include a straight cylinder 24 and a bottom 25 at one end of the straight cylinder 24.

As shown in fig. 4, the first housing 22 and the second housing 23 are interposed. The opposite insertion means that the open ends 19 of the first housing 22 and the second housing 23 are opposite to each other for insertion. The straight cylinder 24 of the first housing 22 is located outside the straight cylinder 24 of the second housing 23. A receiving chamber is formed between the first housing 22 and the second housing 23. The battery cell is positioned in the accommodating cavity. The two bottom portions 25 are respectively abutted against the two conductor portions 11. Thus, the first case 22 and the second case 23 serve as one electrode of the battery, respectively.

The two bottom portions 25 may have through holes formed at positions corresponding to the respective conductor portions 11 so that the conductor portions 11 can pass through the through holes. The two conductor portions 11 serve as the positive electrode and the negative electrode of the battery, respectively.

Sealing rings 31 are arranged between the upper and lower ends of the battery cell and the inner wall of the shell. The seal ring 31 is used to insulate the battery cell from the case and can function as a seal case, for example, the seal ring is cured by a sealant. The support plate 12 is provided with a through hole to facilitate injection of the electrolyte.

In this example, the first housing 22 and the second housing 23 are each straight cylindrical. The straight cylindrical structure can save space inside the receiving chamber with respect to the manner of forming a stepped structure at the open end 29 of the first housing 22 and the bottom 25 of the second housing 23 for snap-engagement, so that more pole piece units 19 can be received, thereby improving the capacity of the battery.

The straight tubular structure enables relative movement between the first housing 22 and the second housing 23 in the axial direction, which is unfavorable for the stability of the housing. In one example, as shown in fig. 4, 5 or 9, the straight cylinder 24 of the first housing 22 and the straight cylinder 24 of the second housing 23 are provided with a protrusion and/or a recess 28 at positions corresponding to each other, so that the first housing 22 and the second housing 23 are engaged. For example, the convex portion is an annular convex formed by rolling or a plurality of convex points formed by punching. The recess 28 is an annular groove formed by rolling or a plurality of pits formed by punching. By forming the protruding portion and/or the recessed portion 28, the first casing 22 and the second casing 23 can be effectively clamped together, preventing the first casing 22 and the second casing 23 from moving relatively in the axial direction, and improving the integrity and stability of the battery.

While certain specific embodiments of the invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A battery comprising a cell including a pole piece unit and a stem, the pole piece unit being wound on an outer side of the stem, characterized in that the stem includes at least one electrical connection portion including an elastic element, a main body portion, and a conductor portion at one end of the main body portion, the elastic element being configured to form a pre-elastic force on the conductor portion so as to bring the conductor portion into abutment with a device other than the cell, one current collector at an inner side of the pole piece unit being connected to the stem and being in conduction with the conductor portion;

The main body part comprises a cylindrical part, the elastic element and the conductor part are both positioned in the inner cavity of the cylindrical part, the opening end of the cylindrical part is provided with a stop part for preventing the conductor part from falling off, one end of the elastic element is propped against the main body part or other parts of the core column, and the other end of the elastic element is propped against the conductor part;

the cylindrical part comprises a conductor layer and an insulating layer covering the outside of the conductor layer, a through hole is formed in the side wall of the cylindrical part, the current collector penetrates through the through hole and is communicated with the conductor layer, and the conductor layer is communicated with the conductor part;

The battery cell comprises an insulating part and two electric connection parts positioned at two ends of the insulating part along the axial direction, and conductor parts of the two electric connection parts are positioned at one end, far away from the insulating part, of the main body part;

The battery also comprises a shell, wherein the shell comprises a first shell and a second shell, the first shell and the second shell both comprise a straight cylinder body and bottoms positioned at one end of the straight cylinder body, the first shell and the second shell are inserted in each other, the straight cylinder body of the first shell is positioned at the outer side of the straight cylinder body of the second shell, a containing cavity is formed between the first shell and the second shell, the battery core is positioned in the containing cavity, and the two bottoms are respectively propped against the two conductor parts; or alternatively

2. The battery of claim 1, wherein the current collector is connected to the conductor layer by welding or conductive glue.

3. The battery of claim 1, further comprising support plates disposed at both ends of the stem, the stem and the two support plates being connected together to form an i-shaped structure, the pole piece unit being located between the two support plates.

4. A battery according to claim 3, wherein a notch is provided in at least one of the support plates, the notch being configured for one of the current collectors to protrude from within the i-shaped structure.

5. A battery according to claim 3, wherein the support plate is detachably connected to the stem.

6. The battery according to claim 1, wherein the straight cylinder of the first housing and the straight cylinder of the second housing are provided with a convex portion and/or a concave portion at positions corresponding to each other to cause the first housing and the second housing to be engaged.