CN211719633U

CN211719633U - Secondary lithium ion bean type battery

Info

Publication number: CN211719633U
Application number: CN202020328134.7U
Authority: CN
Inventors: 李桂平; 葛辉明; 李碧梅; 李念; 袁中直; 祝媛; 刘金成
Original assignee: Eve Energy Co Ltd
Current assignee: Eve Energy Co Ltd
Priority date: 2020-03-16
Filing date: 2020-03-16
Publication date: 2020-10-20
Anticipated expiration: 2030-03-16

Abstract

The utility model discloses a secondary lithium ion bean type battery, including shell and the electric core of setting in the shell, the shell includes drain pan and block, drain pan and block are the metalwork, the drain pan includes that bottom plate and ring establish the first leg at a side of bottom plate, the block includes that roof and ring establish the second leg at a side of roof, second leg cover is established outside first leg, the surface paste of first leg has first insulation seal membrane, the internal surface paste of second leg has second insulation seal membrane, first insulation seal membrane solidifies for an organic whole sealing layer with second insulation seal membrane butt back, wherein, the second leg includes a plurality of exterior wall boards that are the contained angle connection in proper order along its axial, first leg includes a plurality of interior wall boards that become the contained angle connection in proper order along its axial, first leg and second leg cooperation are supported tight sealing layer. The utility model discloses a secondary lithium ion bean type battery simple structure, it is sealed effectual, space utilization and energy density are high.

Description

Secondary lithium ion bean type battery

Technical Field

The utility model relates to the technical field of batteries, especially, relate to a secondary lithium ion bean type battery.

Background

A bean cell is a very small size cell, also known as a button cell or button cell. The bean type battery generally comprises a bottom shell, a cover cap and an electric core arranged in a containing cavity formed by the bottom shell and the cover cap, and the sealing difficulty of the bean type battery is very large due to the very small size of the bean type battery. The conventional assembly process for a bean cell is as follows: and (4) sleeving the sealing ring on the bottom shell, placing the battery cell and the like, and covering the cap on the bottom shell for sealing treatment. The bean-type battery thus prepared has the following drawbacks: 1. the upper end of the sealing ring is generally provided with a hook structure to be hung on the top of the bottom shell, the structure and the assembly sealing process of the sealing ring are complex, the manufacturing cost is high, the online production time of the bean type battery can be prolonged, and the capacity can be reduced; 2. the sealing ring part is positioned on the inner wall of the bottom shell, so that the space inside the bottom shell is occupied, and the space utilization rate and the energy density of a battery are reduced; 3. the bean type battery is small in size, so that the thickness of the sealing ring needs to be very thin, the manufacturing difficulty of the sealing ring is increased, meanwhile, the consistency of the thickness and the size of the thin sealing ring is difficult to guarantee, and the sealing performance of the assembled battery is poor.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides an aim at: the secondary lithium ion bean type battery is simple in structure, good in sealing effect, high in space utilization rate and high in energy density.

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

the utility model provides a secondary lithium ion bean type battery, includes the shell and sets up electric core in the shell, the shell includes drain pan and block, the drain pan with the block is the metalwork, the drain pan includes the bottom plate and encircles the first leg of establishing a side of bottom plate, the block includes the roof and encircles the second leg of establishing a side of roof, the second leg cover is established outside the first leg, the surface paste of first leg has first insulating seal membrane, the internal surface paste of second leg has second insulating seal membrane, solidify into an organic whole sealing layer after first insulating seal membrane with second insulating seal membrane butt;

the second surrounding wall comprises a first outer wall plate, a second outer wall plate and a third outer wall plate which are sequentially connected along the axial direction of the second surrounding wall, the first outer wall plate is vertically connected with the top plate, and the second outer wall plate inclines towards one side far away from the center of the second surrounding wall;

the third outer wall plate inclines towards one side of the center of the second surrounding wall, or the third outer wall plate comprises a first sub wall plate and a second sub wall plate which are arranged at an included angle, the first sub wall plate is connected with the second outer wall plate and is vertical to the top plate, and the second sub wall plate inclines towards one side of the center of the second surrounding wall;

the first enclosing wall comprises a first inner wall plate, a second inner wall plate, a third inner wall plate, a fourth inner wall plate and a fifth inner wall plate which are sequentially connected along the axial direction of the first enclosing wall, the fifth inner wall plate is vertically connected with the bottom plate, the fourth inner wall plate faces to the inner part of the first enclosing wall, the third inner wall plate and the first inner wall plate are perpendicular to the bottom plate, the second inner wall plate faces to the outer part of the first enclosing wall, the first outer wall plate is parallel to the first inner wall plate and passes through the sealing layers, the second outer wall plate and the second inner wall plate are parallel to each other and pass through the sealing layers, and the third outer wall plate is located on one side of the third inner wall plate and the fourth inner wall plate.

As a secondary lithium ion beans formula battery's an preferred scheme, the surface of drain pan all sets up first insulation seal membrane, the bottom plate surface be provided with the first hole of dodging on the first insulation seal membrane, the internal surface of block all sets up second insulation seal membrane, the roof internal surface be provided with the second on the second insulation seal membrane and dodge the hole, one of them utmost point ear of electricity core passes the second dodge the hole with roof internal surface welds, another utmost point ear of electricity core with the internal surface welds of bottom plate.

As a preferable aspect of the secondary lithium ion bean type battery, the cell is a winding type cell or a laminated type cell.

As a preferable scheme of the secondary lithium ion bean battery, the battery cell is a winding battery cell, and a pole piece of the winding battery cell comprises a current collector and an active material coated on the current collector;

the current collector is provided with an extension part which extends to the outside of the active material along the radial direction of the winding type battery cell, the extension part is folded and then partially overlapped, the extension part and the pole piece are arranged in an included angle, and the extension part forms a pole lug; or, the part of the current collector extending to the outside of the active material along the axial direction of the winding type battery cell forms the tab; or, the current collector of the winding type battery cell is provided with an empty foil area, one end of the tab is welded in the empty foil area, and the other end of the tab is connected with the shell.

As a preferable scheme of the secondary lithium ion bean battery, the battery cell is a winding battery cell, and the winding battery cell includes a positive plate, a negative plate and a diaphragm arranged between the positive plate and the negative plate;

the diaphragm is provided with an isolation part extending to two ends of the negative plate along the axial direction of the winding type battery cell, and the isolation part is used for isolating a lug of the winding type battery cell from the end surface of the winding type battery cell; or, two terminal surfaces of coiling formula electricity core all are provided with the insulating piece, the insulating piece is used for keeping apart the utmost point ear of coiling formula electricity core with the terminal surface of coiling formula electricity core.

As a preferable aspect of the secondary lithium ion bean battery, all of the separators are inclined toward the center of the wound cell.

As a preferable scheme of the secondary lithium ion bean battery, a necking part is formed at one end of the second surrounding wall, which is far away from the top plate, and the end part of the necking part abuts against the outer wall of the first surrounding wall or the outer wall of the bottom plate; or the like, or, alternatively,

one end of the second surrounding wall, which is far away from the top plate, is abutted against the outer wall of the first surrounding wall.

As a preferred scheme of the secondary lithium ion bean battery, the battery cell is a winding battery cell, the secondary lithium ion bean battery further includes an auxiliary component, the auxiliary component is a cylinder structure with openings at two ends, and has a first end and a second end which are arranged oppositely, one end of the winding battery cell, which is far away from the bottom plate, is inserted into the first end, and the second end is located above the winding battery cell.

As a preferable mode of the secondary lithium ion bean type battery, the auxiliary member is formed by winding a gummed paper, and the first end of the auxiliary member is adhered to the outer peripheral part of the winding type battery cell; or the like, or, alternatively,

the material of the auxiliary piece is consistent with that of a diaphragm of the winding type battery cell, and the auxiliary piece is wrapped on the peripheral part of the winding type battery cell; or the like, or, alternatively,

the auxiliary part and the winding type battery cell are of an integrated structure.

In a preferred embodiment of the secondary lithium ion bean battery, the insulating sealing film is any one of a CPP film, a PPA film, a modified PP film, and a composite film layer of PPA and PP.

The utility model discloses beneficial effect does: the insulating sealing films are respectively stuck to the contact positions of the first surrounding wall and the second surrounding wall, so that the thickness consistency of the insulating sealing films stuck to the two surrounding walls is good, the sealing effect can be improved, the insulating sealing films can be very thin, the space utilization rate in the shell can be further increased, and the energy density of the battery can be improved; the two layers of insulating sealing films are solidified into the sealing layer, primary sealing is realized when the two layers of insulating sealing films are abutted, secondary sealing is realized when the two layers of insulating sealing films are solidified into the sealing layer, and the sealing property between the bottom shell and the cover cap is greatly improved by twice sealing; through set up the toper on first leg and second leg and support the tight structure, this structure can compress tightly the sealing layer between first leg and second leg, is showing the leakproofness that has promoted between drain pan and the lid.

Drawings

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

Fig. 1 is a schematic cross-sectional view of a secondary lithium ion bean battery according to a first embodiment of the present invention.

Fig. 2 is an exploded view of fig. 1.

Fig. 3 is a schematic cross-sectional view of a secondary lithium ion bean battery according to a second embodiment of the present invention.

Fig. 4 is a schematic cross-sectional view of a secondary lithium ion bean battery according to a third embodiment of the present invention.

Fig. 5 is a schematic cross-sectional view of a secondary lithium ion bean battery according to a fourth embodiment of the present invention.

Fig. 6 is a schematic cross-sectional view of a secondary lithium ion bean battery according to a fifth embodiment of the present invention.

Fig. 7 is a schematic structural view of a pole piece and a tab according to an embodiment of the present invention.

Fig. 8 is a schematic structural view of a pole piece and a tab according to another embodiment of the present invention.

In the figure:

1. an electric core; 11. a tab; 111. a positive tab; 112. a negative tab; 12. pole pieces; 121. a positive plate; 122. a negative plate; 13. a diaphragm; 131. an isolation section; 14. an extension portion; 15. a reinforcement;

2. a bottom case; 21. a base plate; 22. a first enclosure wall; 221. a first inner wall panel; 222. a second inner wall panel; 223. a third inner wall panel; 224. a fourth inner wall panel; 225. a fifth inner wall panel;

3. capping; 31. a top plate; 32. a second enclosure wall; 321. a first exterior wall panel; 322. a second fascia panel; 323. a third exterior wall panel; 33. a necking part;

4. a first insulating sealing film; 41. a first avoidance hole;

5. a second insulating sealing film; 51. a second avoidance hole;

6. an auxiliary member.

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.

Referring to fig. 1 and 2, an embodiment of the present invention provides a secondary lithium ion bean type battery, which includes a housing and an electric core 1 disposed in the housing, the housing includes a bottom case 2 and a cap 3, the bottom case 2 and the cap 3 are metal pieces, the bottom case 2 includes a bottom plate 21 and a first wall 22 disposed around a side surface of the bottom plate 21, the cap 3 includes a top plate 31 and a second wall 32 disposed around a side surface of the top plate 31, the second wall 32 is sleeved outside the first wall 22, a first insulating sealing film 4 is pasted on an outer surface of the first wall 22, a second insulating sealing film 5 is pasted on an inner surface of the second wall 32, and the first insulating sealing film 4 and the second insulating sealing film 5 are solidified into an integral sealing layer after being abutted; the second surrounding wall 32 comprises a first outer wall plate 321, a second outer wall plate 322 and a third outer wall plate 323 which are sequentially connected along the axial direction of the second surrounding wall 32, wherein the first outer wall plate 321 is vertically connected with the top plate 31, and the second outer wall plate 322 inclines towards one side far away from the center of the second surrounding wall 32; the third outer wall plate 323 is inclined towards one side of the center of the second surrounding wall 32, or the third outer wall plate 323 comprises a first sub-wall plate and a second sub-wall plate which are arranged at an included angle, the first sub-wall plate is connected with the second outer wall plate 322 and is vertical to the top plate 31, and the second sub-wall plate is inclined towards one side of the center of the second surrounding wall 32; the first enclosing wall 22 comprises a first inner wall plate 221, a second inner wall plate 222, a third inner wall plate 223, a fourth inner wall plate 224 and a fifth inner wall plate 225 which are sequentially connected along the axial direction of the first enclosing wall 22, the fifth inner wall plate 225 is vertically connected with the bottom plate 21, the fourth inner wall plate 224 faces to the inner part of the first enclosing wall 22, the third inner wall plate 223 and the first inner wall plate 221 are vertical to the bottom plate 21, the second inner wall plate 222 faces to the outer part of the first enclosing wall 22, the first outer wall plate 321 and the first inner wall plate 221 are parallel and pass through the sealing layers, the second outer wall plate 322 and the second inner wall plate 222 are parallel and pass through the sealing layers, and the sealing layers on one sides of the third inner wall plate 223 and the fourth inner wall plate 224 are clamped by the third outer wall plate 323. By respectively sticking a layer of insulating sealing film at the contact positions of the first surrounding wall 22 and the second surrounding wall 32, the thickness consistency of the insulating sealing films stuck on the two surrounding walls is good, the sealing effect can be improved, the insulating sealing films can be very thin, the space utilization rate in the shell can be further increased, and the energy density of the battery can be improved; the two layers of insulating sealing films are solidified into the sealing layer, primary sealing is realized when the two layers of insulating sealing films are abutted, secondary sealing is realized when the two layers of insulating sealing films are solidified into the sealing layer, and the sealing performance between the bottom shell 2 and the cover cap 3 is greatly improved by the two times of sealing; by providing the tapered abutting structure on the first surrounding wall 22 and the second surrounding wall 32, the structure can press the sealing layer between the first surrounding wall 22 and the second surrounding wall 32, and the sealing performance between the bottom case 2 and the cap 3 is remarkably improved. Note that: the inclination directions of the outer wall plate and the inner wall plate are determined from the top-down direction.

The first insulating sealing film 4 adhered to the outer surface of the first surrounding wall 22 may be specifically: the outer surface of the first surrounding wall 22 is entirely covered with the first insulating sealing film 4, or the outer surface portion of the first surrounding wall 22 is covered with the first insulating sealing film 4.

Similarly, the second insulating sealing film 5 adhered to the outer surface of the second surrounding wall 32 may be: the outer surface of the second surrounding wall 32 is entirely covered with the second insulating sealing film 5, or the outer surface portion of the second surrounding wall 32 is covered with the second insulating sealing film 5.

The first insulating sealing film 4 and the first surrounding wall 22 may be formed by: firstly, sticking a first insulating sealing film 4 on the surface of a metal piece, then forming a hole at a corresponding position, cutting and punching to form a bottom shell 2, and arranging the first insulating sealing film 4 on the outer surface of a first surrounding wall 22 of the bottom shell 2; secondly, forming holes in the corresponding positions of the first insulating sealing film 4, then adhering the holes to the surface of a metal piece, cutting and punching the metal piece to form the bottom shell 2, and arranging the first insulating sealing film 4 on the outer surface of the first surrounding wall 22 of the bottom shell 2; third, the metal member is cut and punched to form the bottom case 2, and then the first insulating sealing film 4 is stuck to the outer surface of the first peripheral wall 22 of the bottom case 2. The second insulating sealing film 5 and the second surrounding wall 32 are formed in the manner described above.

Preferably, the surface of drain pan 2 all sets up first insulating seal membrane 4, the bottom plate 21 surface be provided with first dodge hole 41 on the first insulating seal membrane 4, the internal surface of block 3 all sets up second insulating seal membrane 5, roof 31 internal surface be provided with the second on the second insulating seal membrane 5 and dodge hole 51, preferably, with the size setting of first dodge hole 41 unanimous with the size of bottom plate 21 for the surface of whole bottom plate 21 can expose. One tab 11 of the battery cell 1 penetrates through the second avoidance hole 51 to be welded to the inner surface of the top plate 31, and the other tab 11 of the battery cell 1 is welded to the inner surface of the bottom plate 21. Insulating seal membrane is pasted entirely to one of them side of drain pan 2 and block 3, the drain pan 2 and the first insulating seal membrane 4 of metal, the block 3 and the second insulating seal membrane 5 of metal all form metal plastic film spare, make whole shell adopt metal plastic film spare to make, need not to set up the sealing washer alone and seal the junction of drain pan 2 and block 3, make fashioned drain pan 2 and block 3 from taking seal structure (being insulating seal membrane) after the metal plastic film spare supplied materials, this process of installation sealing washer has been saved, the production efficiency is promoted, the production cost is reduced. In addition, the arrangement of the first avoidance hole 41 facilitates the conduction of the bottom case 2 and the outside, and the arrangement of the second avoidance hole 51 facilitates the electric connection of the tab 11 and the cap 3. The second avoiding hole 51 is formed in the position, corresponding to the tab 11 to be welded, of the second insulating sealing film 5 on the inner surface of the cap 3, and when the second avoiding hole 51 is formed, attention is paid to the fact that the second insulating sealing film cannot penetrate through the top plate 31 of the cap 3, the first avoiding hole 41 is formed in the first insulating sealing film 4 on the outer surface of the bottom shell 2, and attention is paid to the fact that the first avoiding hole 41 cannot penetrate through the bottom plate 21.

The shell is made of a metal plastic film piece, the hardness of the shell is high, the appearance form of the whole secondary lithium ion bean type battery can be guaranteed to be unchanged, and the situation that the shell deforms due to air expansion in the secondary lithium ion bean type battery can be effectively prevented.

The bottom case 2 and the cap 3 may be a single metal or an alloy material. In the present embodiment, both the bottom case 2 and the cap 3 are stainless steel. In addition, under the premise of ensuring the mechanical strength, metal foil materials can be further adopted, such as: steel foil, and thus, the weight of the battery can be further reduced.

The secondary lithium ion bean type battery is small in size, for example: the diameter is 10mm-13mm, the height is 3mm-6mm, correspondingly, the thickness of the first insulating sealing film 4 and the second insulating sealing film 5 needs to be 0.02mm-0.06mm, the insulating sealing films are directly adhered to metal parts in an outsourcing factory to form metal plastic film parts, after metal plastic film parts are purchased, the metal plastic film parts are cut, stamped and the like to form a shell, the inner surface and the outer surface of the bottom shell 2 and the outer surface of the cover cap 3 need to be clearly distinguished during stamping, so that the first insulating sealing film 4 on the bottom shell 2 after manufacturing and forming is ensured to be located on the outer surface of the bottom shell 2, and the second insulating sealing film 5 on the cover cap 3 is located on the inner surface of the cover cap 3. In other embodiments, the manufactured shell can be purchased directly, that is, when the bottom shell 2 and the cap 3 are purchased, the shape is formed, and the insulating sealing film is pasted at the corresponding position.

The first insulating sealing film 4 and the second insulating sealing film 5 are both CPP films, PPA films, modified PP films, or composite film layers of PPA and PP.

Compared with other films such as LLDPE, LDPE, HDPE, PET, PVG and the like, the CPP film (namely the casting polypropylene film) has the advantages of lower cost, higher yield, higher stiffness than the PE film, excellent moisture and peculiar smell barrier property, can be used as a base film of a composite material, and can be subjected to metallization treatment.

The PPA film (i.e., polyphthalamide film) is a semi-aromatic polyamide made from terephthalic acid or phthalic acid, and PPA has a semi-crystalline state and a non-crystalline state, has a glass transition temperature of about 255 ℃, and is excellent in heat resistance. In addition, PPA also has better chemical resistance, relatively lower moisture absorption rate, and is stronger and harder than fatty polyamides such as nylon and the like.

Polypropylene (PP) is a semi-crystalline thermoplastic plastic with high impact resistance, high mechanical properties and resistance to corrosion by various organic solvents and acids and bases.

The modified PP film, namely the modified polypropylene film, is also called as a calcium plastic film, has good dimensional stability, low price, higher rigidity, heat resistance and the like compared with pure PP to a certain extent.

In a specific embodiment of the present invention, the third outer wall plate 323 is perpendicular to the top plate 31 after the cap 3 is formed, and after the cap 3 is assembled on the bottom shell 2, the end of the third outer wall plate 323 away from the second outer wall plate 322 is pressed toward the first wall 22, so that the third outer wall plate 323 of the cap 3 after being assembled is in a state of being inclined toward the inside of the second wall 32.

Of course, the third outer wall plate 323 is not limited to be inclined to a side facing the center of the second surrounding wall 32 as a whole, and the third outer wall plate 323 may be provided in other structures, for example, the third outer wall plate 323 includes a first sub-wall plate and a second sub-wall plate which are arranged at an included angle, the first sub-wall plate is connected to the second outer wall plate 322 and perpendicular to the top plate 31, the second sub-wall plate is inclined to a side facing the center of the second surrounding wall 32, the first sub-wall plate and the third inner wall plate 223 are parallel and abut against each other through the sealing layer, and the second sub-wall plate and the fourth inner wall plate 224 are parallel and abut against each other through the sealing layer, in this case, preferably, the second outer wall plate 322 and the second sub-wall plate are symmetrically arranged along the first sub-wall plate.

In one embodiment, referring to fig. 1 and 2, a necking portion 33 is formed at an end of the second wall 32 away from the top plate 31, and an end of the necking portion 33 abuts against an outer wall of the first wall 22. The provision of the notch portion 33 can effectively prevent the cap 3 from coming off the bottom case 2, and can further improve the sealability between the bottom case 2 and the cap 3.

Of course, the end of the necking portion 33 is not limited to abut on the outer wall of the first wall 22, and as shown in fig. 1 and 2, it is also possible to set the second wall 32 of the cap 3 long enough to extend to the side of the bottom plate 21 away from the end of the first wall 22 after the cap 3 is assembled on the bottom shell 2, and then to perform necking on the necking portion 33 of the second wall 32, in which the necking portion 33 abuts on the outer wall of the bottom plate 21.

Alternatively, the end of the second wall 32 may be directly abutted against the outer wall of the first wall 22 without forming the notch 33 as shown in fig. 3.

The battery cell 1 of the secondary lithium ion bean battery may be a winding type battery cell 1 (as shown in fig. 1 to 5) or a laminated type battery cell 1 (as shown in fig. 6), and the winding type battery cell 1 is taken as an example below.

The winding type battery cell 1 can be in a cylindrical shape, a square column shape, an elliptic column shape and the like.

The winding type battery cell 1 comprises a pole piece 12, a diaphragm 13 and a pole lug 11, wherein the pole piece 12 comprises a positive pole piece 121 and a negative pole piece 122, the pole lug 11 comprises a positive pole lug 111 and a negative pole lug 112, the positive pole lug 111 is connected with the positive pole piece 121, the negative pole lug 112 is connected with the negative pole piece 122, and the positive pole piece 121, the diaphragm 13 and the negative pole piece 122 are sequentially overlapped and then wound to form the winding type battery cell 1.

A positive tab 111 is arranged on a positive plate 121 of the winding type battery cell 1, a negative tab 112 is arranged on a negative plate 122, the positive tab 111 and the negative tab 112 are respectively led out from two ends of the winding type battery cell 1, wherein the positive tab 111 is welded with the cap 3, and the negative tab 112 is welded with the bottom case 2. The positive tab 111 is not limited to be led out from the upper end of the winding type cell 1, and the negative tab 112 is led out from the lower end of the winding type cell 1, but the leading positions of the positive tab 111 and the negative tab 112 may be interchanged, that is, the positive tab 111 is led out from the lower end of the winding type cell 1 to be welded with the bottom case 2, and the negative tab 112 is led out from the upper end of the winding type cell 1 to be welded with the cap 3.

The positive electrode tab 111 and the negative electrode tab 112 are not limited to being disposed at both ends of the wound cell 1, and may be disposed at the same end of the wound cell 1.

In an embodiment, the positive electrode tab 121 and the negative electrode tab 122 are similar in shape, each electrode tab 12 includes a current collector and an active material coated on the current collector, the current collector has an extension portion 14 extending to the outside of the active material along the radial direction of the wound electrical core 1, the extension portion 14 is partially overlapped after being bent, the extension portion 14 and the electrode tab 12 are arranged at an included angle, and the extension portion 14 forms the tab 11. Extension 14 through the mass flow body with pole piece 12 extends to the outside of active material and directly forms utmost point ear 11 after buckling, has saved utmost point ear 11 welded process, has promoted production efficiency, has reduced the internal resistance of coiling formula electricity core 1, and integrated into one piece's utmost point ear 11 and pole piece 12 intensity are higher simultaneously, are difficult for breaking away from.

Of course, the current collector has an extension portion 14 extending to the outside of the active material along the axial direction of the wound electric core 1, the extension portion 14 is directly formed into the tab 11 without bending, specifically, the extension portion 14 is provided in the length direction of the positive electrode sheet 121 or the negative electrode sheet 122 having the long shape, when winding along the length direction of the positive electrode sheet 121 or the negative electrode sheet 122 having the long shape, the extension portions 14 are directly formed at both ends of the axial direction of the wound electric core 1, and then the extension portion 14 of the positive electrode sheet 121 is made into the positive electrode tab 111, and the extension portion 14 of the negative electrode sheet 122 is made into the negative electrode tab 112, respectively.

Preferably, the superimposed position of the extension 14 is provided with a reinforcement 15. Through set up extra reinforcement 15 in extension 14's coincide position, reinforcement 15 can strengthen the intensity of folding coincide position, is prevented effectively that extension 14 from being broken after bending, protects the integrality of utmost point ear 11, has also strengthened the bulk strength of utmost point ear 11 simultaneously.

The bending angle of the extension portion 14 is flexibly adjusted according to the requirement of the winding type battery cell 1 during packaging, specifically, the extension portion 14 is bent by taking the position connected with the end of the pole piece 12 as a pivot, and is bent by a first included angle α, wherein the first included angle α is 90 °, so that the extension portion 14 can be conveniently led out from the two ends of the winding type battery cell 1, the length of the tab 11 is shortened, and the manufacturing cost is reduced. Of course, the bending angle of the extending portion 14 is not limited to 90 °, and the first included angle α may be set to 30 °, 45 °, 100 °, or 120 ° as required.

In a preferred embodiment of the present invention, as shown in fig. 7, the reinforcement member 15 is an adhesive tape wrapped on the outside of the overlapping position of the extension portion 14. Set up the reinforcement 15 into the sticky tape, on the one hand can cushion extension 14 in the coincide position after buckling, can slow down the stress of extension 14 in the department of buckling to a certain extent, effectively reduce the fracture of extension 14 in the coincide position and lead to the phenomenon that utmost point ear 11 and pole piece 12 separate, on the other hand, utilize the sticky tape to play the effect of protection and design to the structure of the coincide position of extension 14, prevent utmost point ear 11 after long-time use, extension 14 takes place to warp and influence the normal use of coiling formula electricity core 1 in the coincide position after buckling. To further enhance the protective effect of the tape on extension 14, multiple layers of tape may be wrapped in an overlapping position.

In another preferred embodiment of the present invention, as shown in fig. 8, the reinforcing member 15 is a double-sided adhesive tape, and the extending portion 14 is provided with a first laminating surface and a second laminating surface which are attached to each other and located at the laminating position, and the double-sided adhesive tape is disposed between the first laminating surface and the second laminating surface. The setting of double faced adhesive tape can prevent effectively that first coincide face and second coincide face from separating to avoid utmost point ear 11 to occupy the space between drain pan 2 and the lid 3.

In addition, the extension part 14 can be bent for multiple times at the same position, so that the thickness of the superposed position is increased, and the strength of the pole piece 12 is further improved.

Certainly, the tab 11 is not limited to be integrally formed with the current collector of the pole piece 12, but may be formed separately, an empty foil area is formed at a reserved position on the current collector of the pole piece 12 without coating an active material, one end of the tab 11 is welded with the empty foil area, and the other end is welded with the bottom case 2 or the cap 3.

In one embodiment, as shown in fig. 4, the separator 13 has a separation part 131 extending to both ends of the negative electrode sheet 122 along the axial direction of the winding type cell 1, and the separation part 131 is used to separate the tab 11 of the winding type cell 1 from the end surface of the winding type cell 1. The setting of isolation 131 can prevent effectively that utmost point ear 11 from taking place the electrical contact with the both ends of the vertical direction of coiling formula electricity core 1, and this isolation 131 and coiling formula electricity core 1 structure as an organic whole need not to set up insulating gasket in addition on the terminal surface of coiling formula electricity core 1, has reduced beans formula battery's the preparation degree of difficulty and cost, has promoted production efficiency, need not to change current beans formula battery's preparation technology and equipment simultaneously, is favorable to beans formula battery's large-scale production, and insulating nature is good.

In this embodiment, the length of the isolation portion 131 extending beyond the end face of the winding type battery cell 1 is not less than 0.75 mm. The design can ensure that the end face of the winding type battery cell 1 formed after the positive plate 121, the negative plate 122 and the diaphragm 13 are wound has the isolating part 131 with enough length so as to insulate and isolate the tab 11 and ensure the insulation effect.

Of course, the isolating part 131 is not limited to be provided to isolate the tab 11 from the end surface of the winding type cell 1, and additional insulating sheets may be provided at the two ends of the winding type cell 1 to isolate the tab 11 from the end surface of the winding type cell 1.

In general, the current collector of the positive electrode tab 121 is an aluminum foil, and the current collector of the negative electrode tab 122 is a copper foil, so the material of the positive electrode tab 111 is an aluminum foil, and the material of the negative electrode tab 112 is a copper foil. The aluminum foil and the copper foil are both softer than an aluminum sheet (tape) or a nickel sheet (tape) which is a material of the conventional tab 11, so that the separator 131 is not easily pierced by the tab 11 when being attached to the end surface of the winding type cell 1.

In order to further improve the safety of the bean cell, a separator 13 having high temperature resistance (130-: an aramid fiber membrane 13.

As shown in fig. 5, the secondary lithium ion bean battery further includes an auxiliary member 6, where the auxiliary member 6 is a cylindrical structure with two open ends and has a first end and a second end that are opposite to each other, one end of the winding type battery cell 1, which is far away from the bottom plate 21, is inserted into the first end, and the second end is located above the winding type battery cell 1. Through setting up auxiliary member 6 in coiling formula electricity core 1's top, this auxiliary member 6 can store electrolyte temporarily, annotate the liquid operation time, annotate liquid equipment and pour into the inside of auxiliary member 6 with electrolyte, electrolyte enters into coiling formula electricity core 1's gap slowly again to absorbed by coiling formula electricity core 1, can prevent effectively that electrolyte from overflowing, can once only pour into sufficient electrolyte into simultaneously, greatly promoted production efficiency, reduced manufacturing cost.

The first end is connected with the end of the winding type battery core 1 far away from the bottom plate 21, and the design can reduce the occupation of the bottom shell 2 and even the inner space of the shell of the whole bean type battery by the auxiliary part 6 as much as possible. Preferably, the first end of the auxiliary element 6 is connected to the outer periphery of the winding type battery cell 1, so that the space for storing the electrolyte in the auxiliary element 6 can be enlarged, and the connection between the auxiliary element 6 and the winding type battery cell 1 is facilitated.

Preferably, the auxiliary member 6 is a cylinder structure, that is, the size of the first end is equal to the size of the second end, and this design can make the diameters of the inner cavity of the auxiliary member 6 consistent everywhere, and during liquid injection, the pressure of the electrolyte in the inner cavity directly acts on the end of the winding type battery cell 1, so that the pressure of the electrolyte in the inner cavity to the winding type battery cell 1 is increased, the absorption of the winding type battery cell 1 to the electrolyte is more facilitated, and the production efficiency of the bean type battery is improved. Of course, in other embodiments, the auxiliary member 6 may also be set to be a horn structure, and the size of the first end is smaller than that of the second end, so that the electrolyte injection can be facilitated by the design, and the precision requirement on the electrolyte injection device is reduced.

In order to provide reference for the injection amount of the electrolyte in the auxiliary part 6, a liquid level height line is arranged in an inner cavity of the auxiliary part 6, the specific height of the electrolyte needing to be temporarily stored in the inner cavity can be calculated before the electrolyte is injected, and then in the actual electrolyte injection process, the electrolyte can be accurately injected only by controlling the electrolyte on the height, so that the accurate control of the injection amount of the electrolyte is facilitated.

In the present embodiment, the auxiliary 6 is formed by winding a tape, and the first end of the auxiliary 6 is attached to the outer peripheral portion of the wound battery cell 1. Because the adhesive tape is thinner and has certain design effect, with adhesive tape wound into auxiliary member 6, annotating the liquid and accomplish the back, need not dismantle auxiliary member 6 from coiling formula electricity core 1, can directly encapsulate the adhesive tape in the shell that drain pan 2 and block 3 are constituteed, hardly occupy the inner space of shell, be convenient for improve battery energy density, reduce the encapsulation degree of difficulty for bean type battery's production efficiency is high. Specifically, the gummed paper may be made of polypropylene (PP) or polyethylene terephthalate (PET) or Polyimide (PI).

It can also act as a tail-out glue when using gummed paper as auxiliary 6, which can further reduce costs.

In other embodiments, the auxiliary member 6 is not limited to being wound with adhesive tape, and may be wound with other materials that do not affect the performance of the battery, such as the same material as the separator 13.

Or the auxiliary member 6 directly forms an integral structure with the winding type battery cell 1, the size of the diaphragm 13 adjacent to the outer ring can be made large, so that the wound diaphragm 13 forms a circle of structure protruding outward from the end face of the winding type battery cell 1 at the end departing from the bottom plate 21 at the periphery of the winding type battery cell 1, and the structure at least surrounds the periphery of the winding type battery cell 1 by a circle to form the auxiliary member 6. This design makes it possible to dispense with the additional production and installation of the auxiliary element 6, so that the auxiliary element 6 is formed after winding of the wound electrical core 1.

The embodiment of the utility model provides a still provide a manufacturing method of secondary lithium ion bean type battery, place electric core 1 in drain pan 2, and will electric core 1's utmost point ear 11 respectively with drain pan 2 and block 3 welding, then annotate the liquid, will after annotating the liquid block 3 with drain pan 2 equipment is right after the equipment the drain pan 2 with first insulating seal membrane 4 between the block 3 and the solidification of second insulating seal membrane 5 form the one deck sealing layer. The manufacturing method is simple to operate, the step of installing the sealing ring is omitted, the production efficiency is greatly improved, in addition, the thickness consistency of the insulating sealing films on the bottom shell 2 and the cover cap 3 is good, secondary sealing is realized by adopting a curing mode, and the sealing effect is greatly improved.

The first insulating sealing film 4 and the second insulating sealing film 5 are cured by heating or radiation.

The specific preparation method comprises the following steps:

s100, providing a metal piece, and cleaning, drying and passivating the surface of the metal piece;

step S200, adhering an insulating sealing film to one side surface of the metal piece by using an adhesive, and performing hot press molding to form a metal plastic film piece (the metal plastic film piece can also be purchased as a finished product);

step S300, forming a hole in a position corresponding to an insulating sealing film of the metal plastic film piece;

step S400, cutting a metal plastic film piece, and stamping to form a bottom shell 2 and a cap 3, wherein a first insulating sealing film 4 of the bottom shell 2 is positioned on the outer surface of the bottom shell, a second insulating sealing film 5 of the cap 3 is positioned on the inner surface of the bottom shell, a first avoidance hole 41 is formed in the first insulating sealing film 4 of the outer wall of the bottom shell 2, and a second avoidance hole 51 is formed in the second insulating sealing film 5 of the inner wall of the cap 3;

step S500, assembling the battery cell 1 in the bottom case 2, and injecting liquid;

step S600, assembling the bottom shell 2 and the cap 3, heating and fusing the joint of the bottom shell 2 and the cap 3, controlling the heating temperature to be 100-1000 ℃, controlling the heating time to be 1-60S, fusing the first insulating sealing film 4 and the second insulating sealing film 5 into a sealing layer, and enabling no gap to exist between the bottom shell 2 and the cap 3 so as to achieve the effect of complete sealing.

Preferably, the heating temperature may be 150 ℃, 160 ℃, 200 ℃, 250 ℃, 300 ℃, 350 ℃, 400 ℃, 450 ℃, 500 ℃, 550 ℃, 600 ℃, 650 ℃, 700 ℃, 750 ℃, 800 ℃, 850 ℃, 900 ℃, 950 ℃.

Preferably, the heating time may be 2s, 3s, 5s, 8s, 10s, 15s, 20s, 25s, 30s, 35s, 40s, 45s, 50s, 55 s.

The forming of dodging the hole is not limited to be set before bottom shell 2 and block 3 stamping forming, can also directly set up well before making metal plastic film spare, is about to insulating seal membrane corresponds the position trompil, pastes the insulating seal membrane after the trompil on the surface of metalwork. Or, after the bottom shell 2 and the cover cap 3 are punched and formed, the avoidance holes are formed at the corresponding positions.

In this embodiment, the thickness of the metal plastic film member is 100 μm to 300 μm.

The adhesive is polyolefin, polyethyleneimine or polyurethane adhesive resin.

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. The utility model provides a secondary lithium ion beans formula battery, includes the shell and sets up electric core in the shell, its characterized in that, the shell includes drain pan and block, the drain pan with the block is the metalwork, the drain pan includes the bottom plate and encircles the first leg of establishing a side of bottom plate, the block includes the roof and encircles the second leg of establishing a side of roof, the second leg cover is established outside the first leg, the surface paste of first leg has first insulating seal membrane, the internal surface paste of second leg has second insulating seal membrane, solidify into an organic whole sealing layer after first insulating seal membrane with second insulating seal membrane butt;

2. The secondary lithium ion bean type battery of claim 1, wherein the outer surface of the bottom shell is provided with the first insulating sealing film, the outer surface of the bottom plate is provided with a first avoidance hole, the inner surface of the cap is provided with the second insulating sealing film, the inner surface of the top plate is provided with a second avoidance hole, one tab of the battery core passes through the second avoidance hole and is welded to the inner surface of the top plate, and the other tab of the battery core is welded to the inner surface of the bottom plate.

3. The secondary lithium ion bean battery of claim 1, wherein the cell is a wound cell or a laminated cell.

4. The secondary lithium ion bean battery of claim 1, wherein the cell is a wound cell, and the pole piece of the wound cell comprises a current collector and an active material coated on the current collector;

5. The secondary lithium ion bean battery of claim 1, wherein the cell is a wound cell comprising a positive plate, a negative plate, and a separator disposed between the positive plate and the negative plate;

6. The secondary lithium ion bean battery according to claim 5, wherein all of the separators are inclined toward the center of the wound cell.

7. The secondary lithium ion bean-type battery according to claim 1, wherein a necking portion is formed at one end of the second surrounding wall, which is far away from the top plate, and the end of the necking portion abuts against the outer wall of the first surrounding wall or the outer wall of the bottom plate; or the like, or, alternatively,

8. The secondary lithium ion bean battery of claim 1, wherein the battery cell is a wound battery cell, and the secondary lithium ion bean battery further comprises an auxiliary member, the auxiliary member is a two-end-opened cylinder structure and has a first end and a second end that are oppositely arranged, one end of the wound battery cell, which is far away from the bottom plate, is inserted into the first end, and the second end is located above the wound battery cell.

9. The secondary lithium ion bean battery of claim 8, wherein the auxiliary member is formed by winding a gummed paper, and the first end of the auxiliary member is adhered to an outer circumferential portion of the wound battery cell; or the like, or, alternatively,

10. The secondary lithium ion bean-type battery according to claim 1, wherein the insulating sealing film is any one of a CPP film, a PPA film, a modified PP film, and a composite film layer of PPA and PP.