CN212011173U

CN212011173U - Lithium battery

Info

Publication number: CN212011173U
Application number: CN202020615857.5U
Authority: CN
Inventors: 刘亮亮; 祝媛; 刘荣江; 袁中直; 刘建华; 刘金成
Original assignee: Huizhou Yiwei Energy Battery Co ltd; Eve Energy Co Ltd
Current assignee: Eve Energy Co Ltd
Priority date: 2020-04-22
Filing date: 2020-04-22
Publication date: 2020-11-24
Anticipated expiration: 2030-04-22

Abstract

The utility model discloses a lithium battery, which comprises a housin, electric core and shrouding subassembly, the casing includes base plate and leg, form the chamber that holds electric core between leg and the base plate, the one end that the base plate was kept away from to the leg forms and holds the opening that the chamber communicates, shrouding subassembly shutoff opening, the shrouding subassembly includes the body, the interval sets up first connecting piece and second connecting piece on the body, one side that is close to and holds the chamber between first connecting piece and the second connecting piece is formed with the expansion space, one of first connecting piece and second connecting piece between the two is connected with body insulation, first connecting piece has the first connecting portion that extends to between electric core and the leg, a utmost point ear and the first connecting portion of electric core are connected, the second connecting piece has the second connecting portion that extends to between electric core and the leg, another utmost point ear of electric core is connected with. The utility model discloses a lithium cell simple structure, the sealing reliability is high, and the processing degree of difficulty is low, can alleviate the bloated phenomenon of lithium cell.

Description

Lithium battery

Technical Field

The utility model relates to a battery technology field especially relates to a lithium cell.

Background

At present, a lithium battery with a hard shell structure generally comprises a casing and a battery cell, wherein the casing comprises a bottom shell and a cover plate, an opening is formed in the upper end of the bottom shell, the cover plate blocks the opening, the battery cell is placed in the bottom shell, a negative electrode lug of the battery cell is welded with the inner side of the bottom shell, and a positive electrode lug of the battery cell is connected with the cover plate. This type of lithium battery has the following drawbacks: 1. the lithium battery has more parts, complex structure, high processing and production difficulty, is not suitable for batch production and assembly, and has low production efficiency; 2. the battery core is usually assembled in the shell and then welded with the electrode lugs, and the welding is carried out on the inner side of the shell, so that the welding can be carried out only by adopting a laser welding mode, and the compression is required during the laser welding, so that the welding reject ratio is high, and the operation is complex; 3. the special protection needs to be made to the electric core during welding, the influence of heat diffusion to the electric core is prevented, and the cover plate is easy to bulge after being welded during subsequent charging and discharging.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides an aim at: the lithium battery is simple in structure, high in sealing reliability, low in processing difficulty and capable of relieving the swelling phenomenon of the lithium battery.

To achieve the purpose, the embodiment of the present invention adopts the following technical solutions:

the lithium battery comprises a shell, an electric core and a sealing plate assembly, wherein the shell comprises a base plate and an enclosing wall arranged on one side of the base plate in an enclosing mode, an accommodating cavity for accommodating the electric core is formed between the enclosing wall and the base plate, an opening communicated with the accommodating cavity is formed in one end, far away from the base plate, of the enclosing wall, the sealing plate assembly seals the opening, the sealing plate assembly comprises a body, a first connecting piece and a second connecting piece are arranged on the body at intervals, an expansion space is formed between the first connecting piece and the second connecting piece and on one side, close to the accommodating cavity, of the body, one of the first connecting piece and the second connecting piece is in insulation connection with the body, the first connecting piece is provided with a first connecting portion extending between the electric core and the enclosing wall, and a lug of the electric core is connected with the first connecting portion, the second connecting piece is provided with a second connecting portion extending between the battery cell and the surrounding wall, and the other electrode lug of the battery cell is connected with the second connecting portion.

As a preferred aspect of the lithium battery, the battery cell is a winding battery cell, and an axis of the winding battery cell is parallel to the body.

As a preferred embodiment of the lithium battery, two tabs of the battery cell are respectively led out from two ends of the winding battery cell in the axial direction.

As a preferred embodiment of the lithium battery, one tab of the battery cell is welded to a side of the first connecting portion away from the battery cell, and the other tab of the battery cell is welded to a side of the second connecting portion away from the battery cell.

As a preferred scheme of the lithium battery, the first connecting member includes a pole plate assembly, the pole plate assembly includes a first guide plate and a first connecting portion, the first guide plate and one side of the body, which is close to the battery core, are in insulated connection, a first lead-out plate is arranged on the first guide plate, a through hole is formed in the body corresponding to the first lead-out plate, and the first lead-out plate penetrates through the through hole and is exposed on one side of the body, which is far away from the battery core;

the second connecting piece including be the second baffle that the contained angle set up with the second connecting portion, the second baffle with the body is close to one side of electricity core is connected, first baffle with the second baffle forms the support the holding surface of electricity core, the inflation space is located first baffle with between the second baffle.

As a preferable scheme of the lithium battery, the first connecting part and the first guide plate are formed by bending plate-shaped metal; and/or the presence of a gas in the gas,

the second connecting part and the second guide plate are formed by bending plate-shaped metal.

As a preferred scheme of the lithium battery, a liquid injection hole is formed in the body, the second guide plate comprises a first plate right opposite to the liquid injection hole, the first plate is parallel to the body, a second plate extends towards the body from at least one end of the first plate, a third plate is arranged at one end, away from the first plate, of the second plate, the third plate is connected with the second connecting portion, a communication hole for communicating the liquid injection hole with the accommodating cavity is formed between the first plate and the body, and one side, away from the body, of the first plate is abutted to the battery core.

As a preferable scheme of the lithium battery, one end of the surrounding wall, which is far away from the substrate, extends towards the outside of the surrounding wall to form a supporting part, and the body is stacked on the supporting part and is hermetically connected with the supporting part.

As a preferred scheme of lithium cell, the body is by being close to a side orientation of electric core is kept away from a side punching press of electric core is formed with the holding tank, first connecting piece still include with first baffle that first connecting portion are the contained angle and connect, first baffle install in the holding tank, first baffle with set up the first insulation layer between the tank bottom of holding tank, the tank bottom of holding tank runs through and has seted up the through-hole, first baffle is kept away from one side of electric core is connected with first terminal plate, first terminal plate runs through the first insulation layer is located in the through-hole or protrusion in outside the through-hole.

As a preferable mode of the lithium battery, the first insulating layer is any one or a combination of two of a PE layer and a PPa layer; or the like, or, alternatively,

the first insulating layer includes first glue film and the second glue film that the interval set up, first glue film with be provided with the intermediate level between the second glue film, the intermediate level is the PFA layer, first glue film and/or the second glue film does the PE layer or PPa layer.

As a preferred scheme of the lithium battery, the battery cell is a laminated battery cell, a side surface of the laminated battery cell in the thickness direction is parallel to the body, and tabs are led out from the side surface of the laminated battery cell perpendicular to the body.

The utility model discloses beneficial effect does: the first connecting piece and the second connecting piece are arranged on the body of the sealing plate assembly, so that the battery cell can be assembled and welded with the sealing plate assembly in advance during assembly, tab welding is not required after the battery cell is installed in the shell, the tabs are exposed and welded, the battery cell welding device is suitable for various welding modes, automatic assembly can be realized, the welding yield is high, special protection is not required to be performed on the battery cell during welding, and the operation difficulty is reduced; through forming the inflation space between first connecting piece and second connecting piece, the electricity core takes place the inflation when subsequent charge-discharge, can utilize this inflation space to cushion, alleviates the phenomenon of the casing swell of lithium cell effectively.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Fig. 1 is a first perspective view of a lithium battery according to an embodiment of the present invention.

Fig. 2 is a second perspective view of the lithium battery according to the embodiment of the present invention.

Fig. 3 is an exploded perspective view of a lithium battery according to an embodiment of the present invention.

Fig. 4 is the utility model discloses electric core and shrouding subassembly's equipment schematic diagram.

Fig. 5 is a schematic view of the third insulating layer attached to the positive tab of the embodiment of the present invention.

Fig. 6 is the utility model discloses the equipment schematic diagram of electric core, shrouding subassembly and casing.

Fig. 7 is the utility model discloses after electric core, shrouding subassembly and casing equipment and the schematic diagram after the side cut.

Fig. 8 is the schematic diagram of the lithium battery after being filled with liquid and installed with the plugging piece.

Figure 9 is a schematic cross-sectional view of a closure plate assembly according to an embodiment of the present invention.

In the figure:

1. a housing; 11. a substrate; 12. a surrounding wall; 13. an accommodating chamber; 14. a support portion;

2. an electric core; 21. a positive tab; 22. a negative tab;

3. a seal plate assembly; 31. a body; 311. a through hole; 312. a liquid injection hole; 32. a first connecting member; 321. a first connection portion; 322. a first guide plate; 323. a first take-off plate; 33. a second connecting member; 331. a second connecting portion; 332. a second guide plate; 3321. a first plate; 3322. a second plate; 3323. a third plate; 34. a communicating hole;

4. an expansion space; 5. a first insulating layer; 6. a second insulating layer; 7. a blocking member; 8. and a third insulating layer.

Detailed Description

In order to make the technical problems, technical solutions and technical effects achieved by the present invention more clear, the embodiments of the present invention will be described in further detail with reference to the accompanying drawings, and obviously, the described embodiments are only some embodiments, not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present invention.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, detachably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. 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 under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

As shown in fig. 1 to 8, an embodiment of the present invention provides a lithium battery, including a housing 1, a battery cell 2 and a sealing plate assembly 3, the housing 1 includes a substrate 11 and a surrounding wall 12 enclosing on one side of the substrate 11, the surrounding wall 12 and a cavity 13 for accommodating the battery cell 2 formed between the substrate 11, the surrounding wall 12 is far away from one end of the substrate 11 forms an opening communicating with the cavity 13, the sealing plate assembly 3 seals the opening, the sealing plate assembly 3 includes a body 31, a first connecting member 32 and a second connecting member 33 are arranged on the body 31 at intervals, the first connecting member 32 and the second connecting member 33 are arranged between and on the body 31, the body 31 is close to the cavity 13, an expansion space 4 is formed on one side of the cavity 13, one of the first connecting member 32 and the second connecting member 33 is in insulation connection with the body 31, and the other of the first connecting member 32 and the second connecting member 33 is connected with the body 31 and connected with the body 31 Realize the electric continuity, first connecting piece 32 has and extends to electric core 2 with first connecting portion 321 between the leg 12, a utmost point ear of electric core 2 with first connecting portion 321 is connected, second connecting piece 33 has and extends to electric core 2 with second connecting portion 331 between the leg 12, another utmost point ear of electric core 2 with second connecting portion 331 is connected. The first connecting piece 32 and the second connecting piece 33 are arranged on the body 31 of the sealing plate assembly 3, so that the battery cell 2 can be assembled and welded with the sealing plate assembly 3 firstly during assembly, tab welding is not required after the battery cell 2 is installed in the shell 1, and the tabs are exposed and welded, so that the battery cell assembly is suitable for various welding modes, automatic assembly can be realized, the welding yield is high, special protection is not required to be performed on the battery cell 2 during welding, and the operation difficulty is reduced; by forming the expansion space 4 between the first connecting piece 32 and the second connecting piece 33, the battery cell 2 expands during subsequent charging and discharging, and the expansion space 4 can be utilized for buffering, so that the swelling phenomenon of the shell 1 of the lithium battery is effectively relieved.

In the present embodiment, the first connecting member 32 is connected to the positive tab 21 of the battery cell 2, the second connecting member 33 is connected to the negative tab 22 of the battery cell 2, the first connecting member 32 is connected to the body 31 in an insulating manner, and the second connecting member 33 is connected to the body 31 and can be electrically conducted. In other embodiments, positive tab 21 may be connected to second connector 33 and negative tab 22 may be connected to first connector 32.

In this embodiment, the battery cell 2 is a winding battery cell 2, and an axis of the winding battery cell 2 is parallel to the body 31. Through the axis that is on a parallel with body 31 with coiling formula electricity core 2 for coiling formula electricity core 2's utmost point ear is drawn forth from the one end that is close to the lateral wall of casing 1 and is realized the welding, and expansion space 4 is located the side of coiling formula electricity core 2's thickness direction, and coiling formula electricity core 2 is when charging and discharging, and its thickness direction takes place the inflation easily, and this inflation has just in time been alleviated in this expansion space 4, prevents casing 1 or shrouding subassembly 3 effectively and takes place the tympanites. As shown in fig. 4, the thickness direction of the wound battery cell 2 refers to the illustrated vertical direction, i.e., the direction perpendicular to the body 31.

Further, the positive tab 21 and the negative tab 22 are respectively led out from both ends of the winding type cell 2 in the axial direction. This design can be done big with the distance between first connecting piece 32 and the second connecting piece 33, increases the volume in inflation space 4, and can not increase the length and the volume of first connecting piece 32 and second connecting piece 33, has reduced first connecting piece 32 and second connecting piece 33 and has taken up the space that holds chamber 13, has improved the energy density of lithium cell.

The positive tab 21 may be integrally formed with the positive plate of the winding type battery cell 2, that is, the positive plate includes a positive current collector and a positive material coated on the positive current collector, and a portion of the positive current collector extending out of the positive material forms the positive tab 21. Of course, it is also possible to reserve a blank foil area on the positive electrode current collector, and weld the positive electrode tab 21 and the blank foil area of the positive electrode sheet.

The negative electrode tab 22 may be integrally formed with the negative electrode sheet of the winding type battery cell 2, that is, the negative electrode sheet includes a negative electrode collector and a negative electrode material coated on the negative electrode collector, and a portion of the negative electrode collector extending out of the negative electrode material forms the negative electrode tab 22. Of course, it is also possible to reserve a blank foil area on the negative electrode current collector and weld the negative electrode tab 22 to the blank foil area of the negative electrode sheet.

Preferably, the positive tab 21 is welded to the side of the first connection portion 321 facing away from the battery cell 2, and the negative tab 22 is welded to the side of the second connection portion 331 facing away from the battery cell 2. The design can reduce the welding difficulty of the pole lugs, is convenient for realizing automatic production, and further improves the production efficiency and the welding yield.

The first connecting piece 32 includes a pole plate assembly, the pole plate assembly includes a first guide plate 322 and a first connecting portion 321, which are arranged at an included angle, the first guide plate 322 is in insulated connection with one side of the body 31 close to the electric core 2, a first lead-out plate 323 is arranged on the first guide plate 322, a through hole 311 is formed in the body 31 corresponding to the first lead-out plate 323, and the first lead-out plate 323 passes through the through hole 311 and is exposed on one side surface of the body 31 departing from the electric core 2; the second connecting part 33 includes a second guide plate 332 and the second connecting part 331, which are disposed at an included angle, the second guide plate 332 is connected to one side of the body 31 close to the battery cell 2, the first guide plate 322 and the second guide plate 332 form a supporting surface for supporting the battery cell 2, and the expansion space 4 is located between the first guide plate 322 and the second guide plate 332. This structure can minimize the space between electric core 2 and the body 31, reduces spare part on the shrouding subassembly 3 and occupies the space that holds chamber 13, promotes the energy density of battery.

In other embodiments, the first guide plate 322 of the first connecting member 32 may be directly connected to the side of the body 31 close to the battery cell 2 to achieve electrical conduction, and the second guide plate 332 of the second connecting member 33 is connected to the side of the body 31 close to the battery cell 2 in an insulating manner, or the negative tab 22 is directly connected to the first guide plate 322 of the first connecting member 32, and the positive tab 21 is connected to the second guide plate 332 of the second connecting member 33.

In this embodiment, a second insulating layer 6 is further provided, the second insulating layer 6 is provided on a side surface of the battery cell 2 close to the body 31, and the second insulating layer 6 abuts on a supporting surface formed by the first connecting piece 32 and the second connecting piece 33. The second insulating layer 6 can isolate the battery cell 2 from the first connecting piece 32 and the second connecting piece 33, so that insulating isolation is realized.

In an embodiment, the first connecting portion 321 and the first guide plate 322 are formed by bending a plate metal. The pole plate assembly formed by integrally bending is high in structural strength, and is not required to be directly formed by assembly, so that the welding procedures are reduced. Of course, in other embodiments, the first connecting portion 321 and the first guide plate 322 may also be formed by separately cutting metal plates and then integrally assembled by welding.

The second connecting portion 331 and the second guide plate 332 are formed by bending a plate-shaped metal. The integrally bent second connecting member 33 has high structural strength, and is directly formed without assembly, thereby reducing the welding process. Of course, in other embodiments, the second connecting portion 331 and the second guide plate 332 may also be formed by separately cutting metal plates and then integrally assembled by welding.

Specifically, the first connecting portion 321 is perpendicular to the first guide plate 322, and the second connecting portion 331 is perpendicular to the second guide plate 332.

In one embodiment, as shown in fig. 9, the main body 31 has a liquid injection hole 312, the second guide plate 332 includes a first plate 3321 facing the liquid injection hole 312, the first plate 3321 is parallel to the main body 31, at least one end of the first plate 3321 extends toward the main body 31 to form a second plate 3322, one end of the second plate 3322 away from the first plate 3321 is provided with a third plate 3323, the third plate 3323 is connected to the second connection portion 331, a communication hole 34 for communicating the liquid injection hole 312 and the accommodation chamber 13 is formed between the first plate 3321 and the main body 31, and one side of the first plate 3321 away from the main body 31 abuts against the battery cell 2. Through annotating liquid hole 312 setting on body 31, can simplify the structure of casing 1, need not to set up on casing 1 and annotate liquid hole 312, and annotate liquid hole 312 just right with second connecting piece 33 position, can utilize the second connecting piece 33 formation intercommunicating pore 34 of buckling, the electrolyte of being convenient for pours into smoothly, and a part multiple functions has simplified shrouding subassembly 3's structure, has reduced the preparation degree of difficulty.

Further, the second plate 3322 and the third plates 3323 are disposed at two opposite ends of the first plate 3321, one of the third plates 3323 is connected to the second connection portion 331, and both of the third plates 3323 are connected to the main body 31 and located at two sides of the liquid injection hole 312. The two third plates 3323 are more stable and reliable to support.

Specifically, the second guide plate 332 is punched to form a groove with three open sides on the side where the cell 2 is located, one notch of the groove faces the liquid injection hole 312, and the other two notches and the side surface of the body 31 close to the cell 2 jointly define the communication hole 34.

Of course, the second guide plate 332 is not limited to be formed by press molding, and a thicker second guide plate 332 may be directly provided, a groove may be formed, and a hole may be horizontally formed through a groove wall of the groove to serve as the communication hole 34.

In one embodiment, one end of the surrounding wall 12 away from the substrate 11 extends toward the outside of the surrounding wall 12 to form a supporting portion 14, and the body 31 is stacked on the supporting portion 14 and is connected to the supporting portion 14 in a sealing manner. By providing the support portion 14, the assembly of the case 1 and the sealing plate assembly 3 of the lithium battery is facilitated.

In this embodiment, the support portion 14 of the housing 1 is welded to the body 31 of the closure plate assembly 3, and the outer peripheral wall of the body 31 is flush with the end of the support portion 14 remote from the peripheral wall 12. The mode equipment casing 1 and the shrouding subassembly 3 of stitch welding not only can simplify the equipment welding of lithium cell, can also accomplish extremely thin with the thickness of casing 1 and the body 31 of shrouding subassembly 3, and the stitch welding back welds in stitch welding position, because thickness is greater than the thickness of casing 1 and body 31 individual layer structure, consequently can prevent effectively that this position from welding and wear, guarantees the welding effect.

In an embodiment, the body 31 is formed by stamping a containing groove from a side close to the battery cell 2 toward a side far from the battery cell 2, the first guide plate 322 is installed in the containing groove, a first insulating layer 5 is disposed between the first guide plate 322 and a groove bottom of the containing groove, and the first lead-out plate 323 penetrates through the first insulating layer 5 and is located in the through hole 311 or protrudes out of the through hole 311.

In this embodiment, the size of the first guide plate 322 is smaller than the size of the receiving groove, and when the first guide plate 322 is mounted in the receiving groove, the first guide plate 322 does not contact with the groove wall of the receiving groove.

Preferably, the first guide plate 322 is bonded to the first insulating layer 5 by heat sealing, and the first insulating layer 5 is sealed to the receiving groove by heat sealing. The sealing and fixing mode is simple to operate, the insulation and isolation are easy to realize, and the first insulation layer 5 cannot be damaged.

In an embodiment, the first insulating layer 5 is one or a combination of a PE layer and a PPa layer, the first insulating layer 5 may further include a first adhesive layer and a second adhesive layer, an intermediate layer is disposed between the first adhesive layer and the second adhesive layer, the first adhesive layer and/or the second adhesive layer is one of a PE layer and a PPa layer, and the intermediate layer is an FPA layer.

Polyethylene (PE) is a thermoplastic resin obtained by polymerizing ethylene. In industry, copolymers of ethylene with small amounts of alpha-olefins are also included. The polyethylene is odorless, nontoxic, has wax-like hand feeling, excellent low-temperature resistance and good chemical stability, and can resist corrosion of most of acid and alkali. Is insoluble in common solvents at room temperature, has low water absorption and excellent electrical insulation.

Polypropylene (PP) is a polymer formed by propylene addition polymerization, is a white waxy material, is transparent and light in appearance and flammable, has a melting point of 165 ℃, is softened at about 155 ℃, and has a use temperature range of-30-140 ℃. The modified PP (PPa) used in this example is a Metal-philic modified Polypropylene resin (hereinafter, referred to as Metal-philic modified PP) whose surface has a Metal-philic property by a chemical modification method such as copolymerization, grafting or crosslinking, and can be fused with a Metal surface by heating to form a good bonding seal.

PFA is known as tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer (also known as perfluoroalkoxy, soluble polytetrafluoroethylene), which is a copolymer of a small amount of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene. The melt cohesiveness is enhanced, the melt viscosity is reduced, and the performance is unchanged compared with the polytetrafluoroethylene. The resin can be directly processed into products by adopting a common thermoplastic molding method. PFA has excellent chemical corrosion resistance at a long-term use temperature of-200 ℃ to-260 ℃, resists corrosion to all chemicals, has the lowest friction coefficient in plastics, has good electrical property, has no temperature influence on electrical insulation, and is called as 'plastics king'. The PFA has chemical resistance similar to that of polytetrafluoroethylene, better than vinylidene fluoride, better creep resistance and compression strength than that of polytetrafluoroethylene, high tensile strength and elongation of 100-300%; the dielectric property is good, and the radiation resistance is excellent; the flame retardance is high; has no toxicity or harm, has physiological inertia, and can be implanted into human body.

In this embodiment, the first insulating layer 5 comprises two spaced apart layers of PPa with a PFA layer disposed therebetween.

In other embodiments, the battery cell 2 is not limited to a winding battery cell 2, and may also be a laminated battery cell 2, a side surface of the laminated battery cell 2 in the thickness direction is parallel to the body 31, a side surface of the laminated battery cell 2 perpendicular to the body 31 leads out the positive tab 21 and the negative tab 22, and preferably, the positive tab 21 and the negative tab 22 are respectively led out from two opposite side surfaces of the laminated battery cell 2. The thickness direction of the laminated battery cell 2 refers to the direction in which the laminated battery cell 2 is stacked, that is, the direction in which the positive plate, the diaphragm and the negative plate are sequentially stacked.

When electric core 2 is coiling formula electricity core 2, its diaphragm has the extension outside the axis direction that extends to coiling formula electricity core 2's the terminal surface towards coiling formula electricity core 2, and this extension is arranged in keeping apart the terminal surface of coiling formula electricity core 2's axis direction and the inner wall of casing 1 or is arranged in keeping apart the pole piece contact in utmost point ear and the coiling body, promotes insulating effect, need not to set up the insulating layer alone and keeps apart.

When electric core 2 is lamination formula electricity core 2, its diaphragm has the orientation that stretches out towards the utmost point ear and extends to its end extension outside the face, this extension is arranged in keeping apart terminal surface and the inner wall of casing 1 that the utmost point ear of lamination formula electricity core 2 stretches out the orientation or is arranged in keeping apart utmost point ear and the lamination body pole piece contact, promote insulating effect, need not to set up the insulating layer alone and keep apart, lamination formula electricity core 2's anodal ear 21 can with anodal mass flow body integrated into one piece of anodal piece or with anodal piece welded fastening, negative pole ear 22 can with the negative pole mass flow body integrated into one piece of negative pole piece or with negative pole piece welding machine shaping.

When the battery cell 2 is a winding battery cell 2, the winding battery cell 2 is wound into a rectangular body matching the structure of the casing 1, and two end faces of the winding battery cell 2 along the central axis direction are perpendicular to a longer side face of the casing 1 (i.e. a side face in the length direction of the casing 1), i.e. the central axis of the winding battery cell 2 is perpendicular to the width direction of the casing 1 (i.e. the X direction shown in fig. 1), and the Y direction shown in fig. 1 is the length direction of the casing 1. The structure can reduce the space occupation of the cylindrical winding type battery cell 2 at the bending position, and improve the space utilization rate in the shell 1.

In addition, a plugging piece 7 is arranged in the liquid injection hole 312, and the plugging piece 7 is fixed in the liquid injection hole 312 to plug the liquid injection hole after the liquid injection is finished. The plugging piece 7 can be of a solid structure, and the plugging piece 7 of the solid structure can be flush with the outer surface of the body 31, so that the appearance of the lithium battery is improved. In other embodiments, the plugging member 7 may also be a hollow structure, and the plugging member 7 with the hollow structure may reduce the weight of the lithium battery. Specifically, the plugging member 7 includes a plugging body and a plugging portion formed by stamping at the middle of the plugging body, the plugging portion is inserted into the liquid injection hole 312, one side of the plugging body where the plugging portion is protruded abuts against the outer surface of the body 31, and preferably, the plugging body is welded to the outer surface of the body 31.

In an embodiment, a third insulating layer 8 is disposed on a side of the positive tab 21 away from the first connecting portion 321, and the third insulating layer 8 is used for isolating the positive tab 21 from an inner wall of the casing 1 and preventing the positive tab 21 from contacting the casing 1.

The embodiment of the utility model provides a still provides a manufacturing method of lithium cell for making as above arbitrary embodiment the lithium cell, will electric core 2 is placed on shrouding assembly 3, then will electric core 2 positive ear 21 with the welding of the first connecting piece 32 on the shrouding assembly 3, will electric core 2 negative pole ear 22 with the welding of the second connecting piece 33 on the shrouding assembly 3, then will electric core 2 with shrouding assembly 3 structure as an organic whole with casing 1 assembles. Through assembling electric core 2 and shrouding subassembly 3 earlier as an organic whole back again with 1 equipment of casing for utmost point ear can realize exposing the welding, thereby can be applicable to multiple welding mode, for example, laser welding, ultrasonic welding and resistance weld etc. expose welded mode, the heat can not gather in 1 casing, consequently need not to take special protection to electric core 2, has reduced the preparation degree of difficulty, has promoted production speed.

Preferably, an automatic welding production line is provided, the battery cell 2 and the sealing plate assembly 3 are placed on the automatic welding production line, and the automatic welding production line welds the positive tab 21 and the negative tab 22 with the first connecting piece 32 and the second connecting piece 33 respectively. The automatic welding production line assembles welding electric core 2 and shrouding subassembly 3, has greatly promoted the yield of production speed and product.

The lithium battery comprises the following specific manufacturing steps:

step S100, as shown in fig. 4, assembling the first connecting member 32, the second connecting member 33, the body 31 and the first insulating layer 5 into an integrally formed sealing plate assembly 3;

step S200, as shown in fig. 4, inverting the battery cell 2 on the sealing plate assembly 3, placing the second insulating layer 6 between the battery cell 2 and the sealing plate assembly 3, and positioning the battery cell 2 between the first connecting portion 321 and the second connecting portion 331;

step S300, as shown in FIG. 4, the battery cell 2 and the seal plate assembly 3 are placed on an automatic welding production line, the automatic welding production line conveys the battery cell to a welding position, a welding machine at the welding position automatically welds the positive tab 21 and the first connecting piece 32, and welds the negative tab 22 and the second connecting piece 33;

step S400, as shown in fig. 5, attaching a third insulating layer 8 to a side of the positive tab 21 away from the first connection portion 321;

step S500, as shown in fig. 6, placing an assembly formed by assembling the battery cell 2 and the sealing plate assembly 3 in the casing 1, and then welding the body 31 and the supporting portion 14 of the casing 1, wherein sufficient margin is left between the casing 1 and the body 31 of the sealing plate assembly 3 during blanking, so that the body 31 and the supporting portion 14 can be better assembled and welded;

step S600, as shown in fig. 7, drawing a margin line on the body 31 or the support portion 14, and then cutting an unnecessary structure along the margin line;

step S700, as shown in fig. 8, performs liquid injection through the liquid injection hole 312, performs chemical conversion into a component volume after the liquid injection is completed, and finally blocks the liquid injection hole 312 by the block piece 7.

In the description herein, it is to be understood that the terms "upper" and the like are used in a descriptive sense and based on the orientation or positional relationship shown in the drawings for convenience in description and simplicity of operation, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, configuration and operation in a particular orientation, and therefore should not be construed as limiting the present invention.

In the description herein, references to the description of "an embodiment" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be appropriately combined to form other embodiments as will be appreciated by those skilled in the art.

The technical principle of the present invention is described above with reference to specific embodiments. The description is made for the purpose of illustrating the principles of the invention and should not be construed in any way as limiting the scope of the invention. Based on the explanations herein, those skilled in the art will be able to conceive of other embodiments of the present invention without any inventive effort, which would fall within the scope of the present invention.

Claims

1. A lithium battery comprises a shell, an electric core and a sealing plate assembly, wherein the shell comprises a substrate and an enclosing wall arranged on one side of the substrate in a surrounding manner, a containing cavity for containing the electric core is formed between the enclosing wall and the substrate, an opening communicated with the containing cavity is formed at one end, far away from the substrate, of the enclosing wall, the sealing plate assembly blocks the opening, the lithium battery is characterized in that the sealing plate assembly comprises a body, a first connecting piece and a second connecting piece are arranged on the body at intervals, an expansion space is formed between the first connecting piece and the second connecting piece and on one side, close to the containing cavity, of the body, one of the first connecting piece and the second connecting piece is in insulation connection with the body, the first connecting piece is provided with a first connecting part extending to the electric core and the enclosing wall, and a lug of the electric core is connected with the first connecting part, the second connecting piece is provided with a second connecting portion extending between the battery cell and the surrounding wall, and the other electrode lug of the battery cell is connected with the second connecting portion.

2. The lithium battery of claim 1, wherein the cell is a wound cell, and an axis of the wound cell is parallel to the body.

3. The lithium battery of claim 2, wherein two tabs of the battery cell are respectively led out from two ends of the winding type battery cell in the axial direction.

4. The lithium battery of claim 2 or 3, wherein one tab of the cell is welded to a side of the first connecting portion facing away from the cell, and the other tab of the cell is welded to a side of the second connecting portion facing away from the cell.

5. The lithium battery of claim 1, wherein the first connecting member comprises a plate assembly, the plate assembly comprises a first guide plate and a first connecting portion, the first guide plate and the first connecting portion are arranged at an included angle, the first guide plate is in insulated connection with one side of the body, which is close to the battery core, a first lead-out plate is arranged on the first guide plate, a through hole is formed in the body, which corresponds to the first lead-out plate, and the first lead-out plate passes through the through hole and is exposed on one side of the body, which is away from the battery core;

6. The lithium battery of claim 5, wherein the first connecting portion and the first guide plate are formed by bending a plate-shaped metal; and/or the presence of a gas in the gas,

7. The lithium battery of claim 5, wherein the body has a filling hole, the second guide plate includes a first plate facing the filling hole, the first plate is parallel to the body, at least one end of the first plate extends toward the body to form a second plate, one end of the second plate, which is away from the first plate, is provided with a third plate, the third plate is connected to the second connecting portion, a communication hole for communicating the filling hole with the accommodating cavity is formed between the first plate and the body, and a side of the first plate, which is away from the body, abuts against the battery core.

8. The lithium battery as claimed in claim 1, wherein a support portion is formed by extending one end of the surrounding wall away from the substrate towards the outside of the surrounding wall, and the body is stacked on the support portion and hermetically connected with the support portion.

9. The lithium battery of claim 1, wherein the body is formed by stamping a containing groove from a side close to the battery cell toward a side far away from the battery cell, the first connecting member further comprises a first guide plate connected with the first connecting portion at an included angle, the first guide plate is installed in the containing groove, a first insulating layer is arranged between the first guide plate and the bottom of the containing groove, a through hole is formed in the bottom of the containing groove in a penetrating manner, a first lead-out plate is connected to one side, far away from the battery cell, of the first guide plate, and the first lead-out plate penetrates through the first insulating layer and is located in the through hole or protrudes out of the through hole.

10. The lithium battery of claim 9, wherein the first insulating layer is any one or a combination of two of a PE layer and a PPa layer; or the like, or, alternatively,

11. The lithium battery of claim 1, wherein the battery cell is a laminated battery cell, a thickness direction side surface of the laminated battery cell is parallel to the body, and a tab is led out from a side surface of the laminated battery cell perpendicular to the body.