CN111162234A

CN111162234A - Winding type lithium ion battery

Info

Publication number: CN111162234A
Application number: CN202010070951.1A
Authority: CN
Inventors: 刘荣江; 刘亮亮; 梁玉典; 祝媛; 袁中直; 刘建华; 刘金成
Original assignee: Eve Energy Co Ltd
Current assignee: Eve Energy Co Ltd
Priority date: 2020-01-21
Filing date: 2020-01-21
Publication date: 2020-05-15

Abstract

The invention discloses a coiled lithium ion battery, which comprises a shell and a coiled battery cell arranged in the shell, wherein the shell is a metal shell, a lead-out hole is formed in the metal shell, a terminal assembly is fixedly arranged in the lead-out hole, the terminal assembly comprises a base and a metal terminal, a mounting hole is formed in the base in a penetrating way, the metal terminal is inserted in the mounting hole, two ends of the metal terminal are respectively positioned outside the mounting hole, the base and the metal terminal are connected through a solidified adhesive layer, one tab of the coiled battery cell is connected with one end of the metal terminal positioned in the shell, and the other tab is connected with the inner; the pole piece of the winding type battery cell is positioned at or adjacent to the central position of the winding type battery cell and is provided with a pole lug, and the pole lug extends to the outside of the winding type battery cell. The winding type lithium ion battery has the advantages of simple structure, simple and convenient assembly, good sealing effect, large volume energy density of the battery, difficult breakage of the lug and long service life.

Description

Winding type lithium ion battery

Technical Field

The invention relates to the technical field of batteries, in particular to a winding type lithium ion battery.

Background

Due to the limitation of the packaging process, the sealing area of the leading-out part occupies the internal and external space of the battery, so that the volume energy density of the battery is reduced, the terminal leading-out structure is complex, and the assembly and sealing difficulty is increased. In addition, due to the protruding structure of the leading-out positions of the positive and negative terminals of the soft package battery, a certain difficulty is caused in the installation of a battery pack or a circuit protection device assembled by a plurality of single soft package battery cells.

Meanwhile, because the pole piece of the winding type battery cell is positioned at the outermost periphery of the whole winding type battery cell, when the battery is used, the winding type battery cell can be continuously contracted and expanded, so that the pole piece is continuously pulled, and particularly, the phenomenon of breakage easily occurs in the area near the empty foil at the spot welding position of the pole lug with the weakest stress on the pole piece.

Disclosure of Invention

One object of an embodiment of the present invention is to: the winding type lithium ion battery is simple in structure, simple and convenient to assemble, good in sealing effect and large in volume energy density.

Another object of an embodiment of the present invention is to: the winding type lithium ion battery is provided, the tab of the winding type lithium ion battery is not easy to break, and the service life of the winding type lithium ion battery is long.

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

the winding type lithium ion battery comprises a shell and a winding type battery cell arranged in the shell, wherein the shell is a metal shell, a leading-out hole is formed in the shell, a terminal assembly is fixedly arranged in the leading-out hole and comprises a base and a metal terminal, a mounting hole is formed in the base in a penetrating mode, the metal terminal is inserted into the mounting hole, two ends of the metal terminal are respectively located outside the mounting hole, the metal terminal is connected with the hole wall of the mounting hole through a solidified viscose layer, one tab of the winding type battery cell is connected with one end, located in the shell, of the metal terminal, and the other tab is connected with the inner wall of the shell;

the pole piece of the winding type battery cell is positioned at or adjacent to the central position of the winding type battery cell and is provided with the pole lug, and the pole lug extends to the outside of the winding type battery cell.

As a preferable scheme of the winding type lithium ion battery, the base comprises a seat plate, a first convex part is convexly arranged on one side of the seat plate, the mounting hole is formed in the seat plate and penetrates through the first convex part, the first convex part is in plug-in fit with the lead-out hole, and the seat plate abuts against the inner wall of the shell or the outer wall of the shell.

As a preferable mode of the winding type lithium ion battery, the metal terminal at least has a bonding area bonded with the adhesive layer;

the bonding area is provided with a rough layer; or, the combination area is provided with a plurality of combination convex parts protruding out of the surface of the metal terminal.

As a preferable scheme of the winding type lithium ion battery, a reinforcing plate is fixed on the housing, the reinforcing plate is spaced from the lead-out hole, and the connection position of the tab and the housing is located at the reinforcing plate.

As a preferred scheme of the winding type lithium ion battery, chemical pore-forming is arranged on the shell, the chemical pore-forming is spaced from the lead-out hole, and a waterproof breathable film is arranged in the chemical pore-forming.

As a preferable scheme of the wound lithium ion battery, the outer shell includes a base shell and a cover body, the base shell is a shell structure with one end open and the other end sealed, the open end of the base shell is located on one side surface of the outer shell in the thickness direction, and the cover body blocks the open end of the base shell.

In a preferred embodiment of the wound lithium ion battery, the terminal assembly is mounted on a side surface of the base case perpendicular to the cover.

As a preferable scheme of the winding type lithium ion battery, the outer shell is a cylindrical shell, an opening is formed in the arc-shaped side face of the outer shell, and the opening is blocked by a cover body.

In a preferred embodiment of the wound lithium ion battery, a first insulating plate is provided between the metal terminal and an inner wall of the case.

As a preferred scheme of a winding lithium ion battery, a pole piece of the winding cell includes a current collector and an active material coated on the current collector, the current collector has an extension portion extending to the outside of the active material along a radial direction of the winding cell, the extension portion is partially overlapped after being bent, the extension portion and the pole piece form an included angle, and the extension portion forms the tab; or the like, or, alternatively,

the pole piece of coiling formula electricity core includes the mass flow body and coating the active material on the mass flow body, the mass flow body has and follows the axial direction of coiling formula electricity core extends to the outer extension of active material, the extension forms utmost point ear.

As a preferable scheme of the wound lithium ion battery, the wound battery cell includes a positive plate, a negative plate, and a diaphragm disposed between the positive plate and the negative plate, the diaphragm has an isolation portion extending to both ends of the negative plate along an axial direction of the wound battery cell, and the isolation portion is configured to isolate a tab of the wound battery cell from an end face of the wound battery cell; or the like, or, alternatively,

and an insulating part is arranged between the lug and the end face of the winding type battery cell.

The embodiment of the invention has the beneficial effects that: one lug of the winding type battery core is connected with the metal terminal of the terminal assembly, the other lug of the winding type battery core is connected with the shell, only one sealing structure can be arranged on the shell, the sealing structure of the integrated terminal assembly is simple, the occupied space in the shell is small, the volume energy density of the winding type lithium ion battery is large, in addition, the integrated terminal assembly can effectively reduce the installation difficulty, and the sealing and fixing effects can be improved by the solidified adhesive layer; the pole lug is led out to the outside of the winding type battery cell from the central position of the winding type battery cell or the position adjacent to the central position, so that the pulling acting force of the deformation of the winding type battery cell on the pole piece can be effectively reduced, the pole piece is not easy to break, and the service life of the pole piece is prolonged.

Drawings

The invention is explained in more detail below with reference to the figures and examples.

Fig. 1 is a perspective view of a first view angle of a wound lithium ion battery according to an embodiment of the present invention (the terminal assembly is partially shown in an exploded state).

Fig. 2 is a perspective view of a second view angle of a rolled lithium ion battery according to an embodiment of the invention (the terminal assembly is partially shown in an exploded state).

Fig. 3 is a schematic cross-sectional view of a wound lithium ion battery according to an embodiment of the invention.

Fig. 4 is a schematic top view of a rolled lithium ion battery according to an embodiment of the invention (the cover is not shown).

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

Fig. 6 is a schematic cross-sectional view of a wound lithium ion battery according to yet another embodiment of the present invention.

Fig. 7 is an assembly diagram of the pole piece and the tab in an unfolded state according to an embodiment of the invention.

Fig. 8 is an assembly view of a pole piece and a tab in an unfolded state according to another embodiment of the present invention.

Fig. 9 is a schematic cross-sectional view of a wound cell according to an embodiment of the present invention.

Fig. 10 is a schematic structural diagram of a pole piece and a tab according to an embodiment of the invention.

Fig. 11 is a schematic structural view of a pole piece and a tab according to another embodiment of the present invention.

Fig. 12 is a partial cross-sectional view of a base housing of an embodiment of the present invention.

Fig. 13 is a partial cross-sectional view of a base shell of another embodiment of the present invention.

Fig. 14 is a front view of a first insulating plate according to an embodiment of the present invention.

Fig. 15 is a side view of a first insulating plate according to an embodiment of the invention.

In the figure:

1. a housing; 11. a base shell; 111. an installation part; 112. an exit aperture; 12. a cover body; 13. forming a hole; 131. a step surface; 14. a sealing plate; 15. a second convex portion; 16. a limit ring plate;

2. a winding type battery cell; 21. a tab; 211. a positive tab; 212. a negative tab; 22. pole pieces; 221. a positive plate; 222. a negative plate; 23. an extension portion; 231. a superimposed position; 24. a reinforcement; 25. a diaphragm; 251. an isolation section;

3. a terminal assembly; 31. a base; 311. a seat plate; 312. a first convex portion; 313. mounting holes; 32. a metal terminal; 33. an adhesive layer;

4. a first insulating plate; 41. a first plate body; 42. a second plate body;

5. a reinforcing plate;

6. a second insulating plate; 61. a notch;

7. a waterproof breathable film;

8. a sealing plug; 81. air holes are formed; 82. a plug body; 83. and a third convex portion.

Detailed Description

In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within 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, removably 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 meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly 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 to 6, the winding type lithium ion battery disclosed by the present invention includes a housing 1 and a winding type battery cell 2 disposed in the housing 1, where the housing 1 is a metal housing 1, the housing 1 is provided with a lead-out hole 112, a terminal assembly 3 is fixedly disposed in the lead-out hole 112, the terminal assembly 3 includes a base 31 and a metal terminal 32, the base 31 is provided with a mounting hole 313 through which the metal terminal 32 is inserted into the mounting hole 313, two ends of the metal terminal 32 are respectively located outside the mounting hole 313, the metal terminal 32 is connected with a hole wall of the mounting hole 313 through a cured adhesive layer 33, one tab 21 of the winding type battery cell 2 is connected with one end of the metal terminal 32 located in the housing 1, and the other tab 21 is connected with an inner wall of the housing 1. Through being connected a utmost point ear 21 with terminal subassembly 3's metal terminal 32 with coiling formula electricity core 2, another utmost point ear 21 is connected with shell 1, can only set up a seal structure on shell 1, and the seal structure of terminal subassembly 3 of integral type is simple, and it is few to occupy the space in the shell 1 for coiling formula lithium ion battery's volumetric energy density increase, in addition, the terminal subassembly 3 of integral type can also effectively reduce the installation degree of difficulty, and the viscose layer 33 of solidification can promote sealed and fixed effect.

In other embodiments, the base 31 and the metal terminal 32 are not limited to be connected by the cured adhesive layer 33, and a sealing ring may be disposed on an inner wall of the mounting hole 313 of the base 31, and the sealing ring is sleeved outside the metal terminal 32, so that the connection between the base 31 and the metal terminal 32 is sealed and insulated by the sealing ring. In order to further prevent the position of the sealing ring from moving, a circle of mounting groove is annularly arranged in the mounting hole 313, and the sealing ring is clamped in the mounting groove.

The shell 1 is made of metal materials, the hardness is high, the appearance form of the whole winding type lithium ion battery can be guaranteed to be unchanged, and the situation that the shell 1 deforms due to gas expansion in the battery can be effectively prevented.

The metal material may be a single metal material or an alloy material. In the present embodiment, the metal material is 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 winding type battery cell 2 can be in the shape of a square column, a cylinder, an elliptic cylinder and the like, and the shape of the winding type battery cell corresponds to that of the shell 1.

In the present embodiment, as shown in fig. 1 and 2, the housing 1 is rectangular, and the terminal assembly 3 is disposed at one end of the housing 1 in the length direction, that is, the housing 1 is of a flat square structure, and correspondingly, the winding type battery cell 2 is of a square column structure.

Specifically, the housing 1 includes a base shell 11 and a cover 12, the base shell 11 is a shell structure with an opening at one end and a sealing at the other end, the opening end of the base shell 11 is located on one side surface of the housing 1 in the thickness direction, the cover 12 seals the opening end of the base shell 11, and the terminal assembly 3 is mounted on the side surface of the base shell 11 perpendicular to the cover 12. The shell 1 of this structure is more convenient for placing of coiling type electricity core 2 because the opening of base shell 11 is located the ascending one of them side of shell 1 thickness direction, explains that the open-ended size can be accomplished very greatly, and coiling type electricity core 2 is more convenient when placing, and the degree of difficulty is lower, can increase into the shell and compare.

The thickness direction of the casing 1 in the embodiment of the present invention refers to a vertical direction of two parallel side surfaces with a larger area of the casing 1 in the flat structure, that is, the thickness of the casing 1 is a distance between the two parallel side surfaces with a larger area of the casing 1 in the flat structure, and the one side surface in the thickness direction is the side surface with a larger area of the casing 1, and the size of the opening end arranged on the side surface is larger, so that the winding type electric core 2 can be more conveniently placed.

The cover 12 is flat and fixedly connected with the base shell 11 by welding, after the cover 12 is welded in place, the sealing end of the base shell 11 is sealed, and a closed cavity is formed inside the housing 1.

Optionally, the open end of the base shell 11 extends toward the outside of the housing 1 to form a mounting portion 111, and the mounting portion 111 is connected to the cover 12. Through setting up installation department 111, can reduce the equipment degree of difficulty of lid 12 and base shell 11, be revised as the angle joint mode with the welding mode by the butt joint mode, greatly reduced the welding degree of difficulty, promoted welding speed, in addition, can also promote the leakproofness, effectively prevent that electrolyte from leaking outward, simultaneously, after the welding is accomplished, can cut unnecessary installation department 111 and get rid of, so, can further reduce the volume of battery.

In other embodiments, the cover 12 is not limited to be flat, and may be configured to be identical to the base shell 11, that is, the cover 12 is also configured to be a shell with one open end and one closed end, and the open end of the cover 12 and the open end of the base shell 11 are butted or sleeved to achieve sealing, in which case, the terminal assembly 3 may be disposed on the base shell 11 or on the cover 12.

In addition, when the housing 1 is cylindrical, an opening is opened in an arc-shaped side surface of the housing 1, and this opening is closed by the cover 12, and at this time, the cover 12 is of an arc-shaped plate-like structure, and the terminal assembly 3 is mounted on one of end surfaces of the cylindrical housing 1.

In an embodiment, the base 31 of the terminal assembly 3 includes a seat plate 311, a first protrusion 312 is protruded from one side of the seat plate 311, the mounting hole 313 is opened on the seat plate 311 and penetrates through the first protrusion 312, the first protrusion 312 is inserted into and matched with the lead-out hole 112, and the seat plate 311 abuts against an inner wall of the base housing 11 or an outer wall of the base housing 11. The first protrusion 312 is engaged with the seat plate 311, so that the assembly difficulty of the terminal assembly 3 can be reduced, the seat plate 311 can limit the insertion position of the terminal assembly 3, the first protrusion 312 is engaged with the lead-out hole 112, and finally, the terminal assembly 3 is welded to the base housing 11, so as to fixedly connect the terminal assembly 3 to the base housing 11.

In the present embodiment, the seat plate 311 abuts against the outer wall of the base housing 11, and the outer periphery of the seat plate 311 is welded to the base housing 11 by laser welding or resistance welding, thereby achieving sealing and fixing.

As shown in fig. 1, 2, 14 and 15, if the end of the metal terminal 32 located in the base case 11 is too long, it needs to be bent and attached to the inner wall of the base case 11, and the first insulating plate 4 is provided between the metal terminal 32 and the inner wall of the base case 11 in order to prevent the metal terminal 32 and the base case 11 from being electrically connected.

The first insulating plate 4 may be fixed to the inner wall of the base housing 11 by means of an adhesive, or may be fixed to the inner wall of the base housing 11 by means of another fixing means such as a snap-fit connection. First insulation board 4 is the L type, and it includes first plate body 41 and the second plate body 42 of perpendicular connection, and first plate body 41 is pegged graft between the inner wall of base shell 11 and metal terminal 32, carries out the insulation and keeps apart, and second plate body 42 is located the terminal surface of the open end of base shell 11, and first insulation board 4 of L type can carry out the position to it when the installation and prescribe a limit to, reduces the installation degree of difficulty.

In order to increase the connection stability and the sealing performance between the metal terminal 32 and the base 31, a rough layer or a plurality of bonding convex parts protruding from the surface of the metal terminal 32 are arranged in the bonding area of the metal terminal 32 and the adhesive layer 33, and the bonding strength between the metal terminal 32 and the adhesive layer 33 is enhanced by using the rough layer or the bonding convex parts, so that the connection stability and the sealing performance between the metal terminal 32 and the base 31 are improved. Of course, the metal terminal 32 may be provided with a rough layer or distributed with bonding protrusions on the entire surface.

In one embodiment, as shown in fig. 1 to 4, a reinforcing plate 5 is fixed to the base shell 11, the reinforcing plate 5 is spaced from the lead-out hole 112, and the connection position of the tab 21 and the base shell 11 is located at the reinforcing plate 5. The reinforcing plate 5 can increase the thickness of the welding position of the base shell 11 and the pole lug 21, and prevent the base shell 11 from being punctured when the pole lug 21 is welded with the base shell 11.

The reinforcing plate 5 may be disposed at an inner wall of the base housing 11 or an outer wall of the base housing 11. In the present embodiment, the reinforcing plate 5 is located on the outer wall of the base shell 11.

In addition, in order to further prevent the metal sheet located outside the housing 1 from contacting the housing 1, an insulating paste may be applied or an insulating member may be provided on the seat plate 311 located outside the housing 1.

The tab 21 of the winding type battery cell 2 includes a positive tab 211 and a negative tab 212, wherein the negative tab 212 is welded to the metal terminal 32 of the terminal assembly 3, the positive tab 211 is welded to the inner wall of the base shell 11, and the welding position is exactly at the position of the reinforcing plate 5, of course, the positive tab 211 may also be welded to the metal terminal 32 of the terminal assembly 3, the negative tab 212 is welded to the inner wall of the base shell 11, and the welding position is exactly at the position of the reinforcing plate 5.

In the present embodiment, the positive tab 211 and the negative tab 212 are both led out from the same end of the winding type battery cell 2, and the side of the base shell 11 where the terminal assembly 3 is disposed and the side of the base shell 11 where the positive tab 211 is welded are the same side.

In other embodiments, the positive electrode tab 211 and the negative electrode tab 212 are not limited to being led out from the same end of the winding type battery cell 2, and may be disposed at two ends of the winding type battery cell 2, in which case the reinforcing plate 5 and the terminal assembly 3 are disposed on the side surfaces of two ends of the base housing 11 in the longitudinal direction.

In an embodiment, referring to fig. 10 and 11, the pole piece 22 of the winding type battery cell 2 is divided into a positive pole piece 221 and a negative pole piece 222, the positive pole piece 221 and the negative pole piece 222 are similar in shape, each pole piece 22 includes a current collector and an active material coated on the current collector, the current collector has an extension portion 23 extending to the outside of the active material along the radial direction of the winding type battery cell 2, the extension portion 23 is partially overlapped after being bent, the extension portion 23 and the pole piece 22 form an included angle, and the extension portion 23 forms the tab 21. The extending part 23 of the current collector of the pole piece 22 extends to the outside of the active material and is bent to directly form the pole lug 21, so that the process of welding the pole lug 21 is omitted, the production efficiency is improved, the internal resistance of the winding type battery cell 2 is reduced, and meanwhile, the integrally formed pole lug 21 and the pole piece 22 have higher strength and are not easy to separate.

Of course, the current collector has an extension portion 23 extending to the outside of the active material along the axial direction of the winding type battery cell 2, the extension portion 23 is directly formed into the tab 21 without bending, specifically, the extension portion 23 is provided in the length direction of the long strip positive/negative electrode sheet, when winding along the length direction of the long strip positive/negative electrode sheet, the extension portions 23 are directly formed at both ends of the axial direction of the winding type battery cell 2, and then the extension portions 23 of the positive electrode sheet 221 and the extension portions 23 of the negative electrode sheet 222 are respectively welded to become positive/negative electrode tabs.

Preferably, said superimposed position 231 of the extension 23 is provided with a reinforcement 24. Through set up extra reinforcement 24 at the coincide position 231 of extension 23, reinforcement 24 can strengthen the intensity of folding coincide position 231, is prevented effectively that extension 23 from being broken after bending, the integrality of protection utmost point ear 21, has also strengthened the bulk strength of utmost point ear 21 simultaneously.

The bending angle of the extension portion 23 can be flexibly adjusted according to the requirement of the winding type battery cell 2 during packaging, specifically, the extension portion 23 is bent by using the position connected with the end of the pole piece 22 as a pivot, and a first included angle α is bent, wherein the first included angle α is 90 °, and the extension portion 23 can be led out from the two ends of the winding type battery cell 2 conveniently by the angle, so that the length of the tab 21 is shortened, and the manufacturing cost is reduced.

In a preferred embodiment of the invention, as shown in fig. 10, the reinforcement 24 is an adhesive tape wrapped around the outside of the overlapping position 231 of the extension 23. Set up the reinforcement 24 into the sticky tape, on the one hand can cushion extension 23 at the coincide position 231 after buckling, can slow down the stress of extension 23 at the department of buckling to a certain extent, effectively reduce the fracture of extension 23 at coincide position 231 and lead to the phenomenon that utmost point ear 21 and pole piece 22 separate, on the other hand, utilize the sticky tape to play the effect of protection and design to the structure of the coincide position 231 of extension 23, prevent that utmost point ear 21 from taking place to warp and influencing the normal use of wound-type electricity core 2 in the coincide position 231 after buckling after long-time use. To further enhance the protective effect of the tape on the extension 23, multiple layers of tape may be wrapped at the laminating station 231.

In another preferred embodiment of the present invention, as shown in fig. 11, the reinforcing member 24 is a double-sided adhesive tape, and the extending portion 23 is provided with a first laminating surface and a second laminating surface which are attached to each other at the laminating position 231, and the double-sided adhesive tape is disposed between the first laminating surface and the second laminating surface. The double-sided adhesive tape can effectively prevent the first lamination surface and the second lamination surface from being separated, so as to prevent the tab 21 from occupying the space between the base shell 11 and the cover body 12.

In addition, the extension portion 23 can be bent multiple times at the same position, so as to increase the thickness of the overlapping position 231, thereby enhancing the strength of the pole piece 22.

Of course, the tab 21 is not limited to be integrally formed with the current collector of the pole piece 22, but may be formed separately, and an active material is not coated on a predetermined position on the current collector of the pole piece 22 to form a hollow foil region, and one end of the tab 21 is welded to the hollow foil region, and the other end is welded to the metal terminal 32 of the terminal assembly 3 or the housing 1.

In one embodiment, as shown in fig. 9, a separator 25 is disposed between the positive electrode sheet 221 and the negative electrode sheet 222 of the winding type battery cell 2, the separator 25 has a separation portion 251 extending to both ends of the negative electrode sheet 222 along the axial direction of the winding type battery cell 2, and the separation portion 251 is used for separating the tab 21 of the winding type battery cell 2 from the end surface of the winding type battery cell 2. The arrangement of the isolation part 251 can effectively prevent the tab 21 from being electrically contacted with the two ends of the winding type battery cell 2 in the vertical direction, and an insulating gasket is not required to be additionally arranged on the end face of the winding type battery cell 2, so that the preparation difficulty and cost of the winding type lithium ion battery are reduced, the production efficiency is improved, meanwhile, the preparation process and equipment of the existing battery are not required to be changed, the large-scale production of the winding type lithium ion battery is facilitated, and the insulation property is good.

In the present embodiment, the length of the isolation portion 251 extending beyond the end face of the winding type battery cell 2 is not less than 0.75 mm. The design can ensure that the end face of the winding type battery cell 2 formed after the positive plate 221, the negative plate 222 and the diaphragm 25 are wound has the isolation part 251 with enough length so as to insulate and isolate the tab 21 and ensure the insulation effect.

Of course, the provision of the isolation portion 251 to isolate the tab 21 from the end face of the winding type cell 2 is not limited, and as shown in fig. 1 to 6, an additional second insulating plate 6 may be provided to isolate the tab 21 from the end face of the winding type cell 2.

Specifically, as shown in fig. 1 and 2, the second insulating plate 6 is a flat plate, and has a notch 61 through which the negative electrode tab 212 passes. Of course, the number of the notches 61 is not limited to one, and may also be two, that is, one notch 61 is provided for each of the positive tab 211 and the negative tab 212, and the two notches 61 are provided at intervals. Of course, the structure for the tab 21 to pass through is not limited to the notch 61, and a through hole may be provided for the corresponding tab 21 to pass through, and in addition, the design of the notch 61 is also favorable for the electrolyte to permeate into the winding type battery cell 2.

In general, the current collector of the positive electrode sheet 221 is an aluminum foil, and the current collector of the negative electrode sheet 222 is a copper foil, so that the material of the positive electrode tab 211 is an aluminum foil, and the material of the negative electrode tab 212 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, so that the isolation portion 251 is not easily pierced by the tab 21 when being attached to the end surface of the winding type cell 2.

To further improve the safety of the rolled lithium ion battery, a separator 25 having high temperature resistance (130-: an aramid fiber membrane.

The winding type lithium ion battery is a rechargeable battery.

Referring to fig. 1, 12 and 13, the outer side of the base shell 11 referred to in the embodiment of the present invention means: after the base housing 11 is assembled with the cover 12, a side of the base housing 11 facing away from the wound electric core 2, i.e., a side that can be visually observed or manipulated by an operator.

The base shell 11 of the embodiment of the invention is provided with a chemical pore-forming hole 13, the chemical pore-forming hole 13 is internally provided with a waterproof breathable film 7, and the base shell 11 is also provided with a sealing mechanism for plugging the chemical pore-forming hole 13 after the chemical operation is finished. Through arranging the waterproof breathable film 7 in the formation hole 13, the formation hole 13 can be directly utilized for formation operation when the winding type lithium ion battery is subjected to formation operation, and the waterproof breathable film 7 has the characteristics that only gas passes through and moisture cannot pass through, so that external moisture cannot pass through the waterproof breathable film 7 and enter the winding type lithium ion battery, the excellent performance of the winding type lithium ion battery after the formation operation is ensured, meanwhile, the requirement on the drying of the environment can be reduced, the formation operation can be performed in the conventional environment, and the operation difficulty and the energy consumption are further reduced; by arranging the sealing mechanism, the formation hole 13 can be blocked after formation is finished, so that the whole winding type lithium ion battery is in a sealing state.

Preferably, the waterproof breathable film 7 is a polytetrafluoroethylene film (i.e., an E-PTFE film) or a polyurethane film (i.e., a PU film).

In one embodiment, as shown in fig. 12, the hole 13 is integrated with the liquid injection hole of the housing 1, and the waterproof and breathable film 7 is installed in the hole 13 after the liquid injection is completed. Through will become hole 13 and annotate the liquid hole and unite two into one, can reduce the quantity of trompil on basic shell 11, and then reduce the operation degree of difficulty, both can satisfy and annotate the liquid requirement, can cooperate the completion again to become the operation, simplified basic shell 11's structure.

In this embodiment, the hole forming part 13 is a stepped hole, the stepped hole includes a first hole and a second hole that are communicated with each other, the size of the first hole is larger than that of the second hole, a stepped surface 131 is formed at the joint of the first hole and the second hole, and the waterproof breathable film 7 is fixed on the stepped surface 131. By providing the step surface 131, the installation and fixation of the waterproof breathable film 7 can be facilitated.

Specifically, the waterproof breathable film 7 is bonded to the step surface 131. The bonding mode is easy to operate, the fixation can be realized without structures such as extra fasteners, and the disassembly, assembly and replacement are also very convenient.

Further, the first hole is adjacent to the outside of the base shell 11. The larger first hole is adjacent to the outer side of the base shell 11, so that the installation difficulty of the waterproof breathable film 7 can be reduced.

In other embodiments, the formation hole 13 may be a through hole, a taper hole or other hole type.

The sealing mechanism is a sealing plate 14, and the sealing plate 14 is fixed on the outer side of the base shell 11 and blocks the forming hole 13. The sealing plate 14 can seal the injection and the formation hole 13 after the formation is finished, so that the whole sealing performance of the whole winding type lithium ion battery is ensured. Preferably, the sealing plate 14 is welded to the outside of the base shell 11.

In one embodiment, as shown in fig. 13, the chemical conversion hole 13 and the liquid injection hole are not limited to being combined into one, and the chemical conversion hole 13 may be provided separately on the base case 11, and the chemical conversion hole 13 and the liquid injection hole may be provided on the base case 11 at a distance.

In this embodiment, the base shell 11 is provided with a second protrusion 15 protruding outward, the hole 13 is opened on the second protrusion 15 and penetrates through the second protrusion 15 and the base shell 11, the sealing mechanism is a sealing plug 8, and the sealing plug 8 is at least partially inserted into the hole 13 and abuts against the waterproof breathable membrane 7.

Preferably, the sealing plug 8 is provided with a vent hole 81 in a penetrating manner, and the sealing plug 8 can be deformed by external extrusion to block the vent hole 81. The ventilation holes 81 are sealed in a mode of extruding the deformation of the sealing plug 8, so that the sealing operation difficulty can be reduced, and operations such as welding and the like do not need to be performed on the base shell 11.

Specifically, the sealing plug 8 is made of PFA (perfluoroalkoxy resin), the sealing plug 8 made of the PFA can deform through external mechanical extrusion, automatic recovery cannot occur after deformation, the sealing effect can be improved, and the sealing difficulty is effectively reduced. In this embodiment, the protruding second convex part 15 that sets up is more convenient for realize the extrusion operation of sealing plug 8, when concrete operation, presses second convex part 15, makes second convex part 15 warp, and the second convex part 15 of deformation can drive sealing plug 8 in it and take place to warp, and then shutoff bleeder vent 81 realizes lithium ion battery's sealed.

The sealing plug 8 may be installed in the hole 13 from the outside of the base housing 11 or may be installed in the hole 13 from the inside of the base housing 11, and in this embodiment, the sealing plug 8 is installed in the hole 13 from the inside of the base housing 11 in advance.

Specifically, the sealing plug 8 includes a plug body 82 and a third protrusion 83 protruding from one side of the plug body 82, the vent hole 81 is opened on the third protrusion 83, the vent hole 81 is opened through the plug body 82, the third protrusion 83 is inserted into the chemical pore 13 to abut against the waterproof breathable membrane 7, and the plug body 82 abuts against one side of the base shell 11 away from the second protrusion 15.

A limiting ring plate 16 is annularly arranged at one end of the second convex part 15, which is far away from the base shell 11, and is positioned in the chemical pore 13, and the waterproof breathable film 7 is clamped between the limiting ring plate 16 and the sealing plug 8. Set up limit ring board 16 and can provide the mounting plane for waterproof ventilated membrane 7, reduce the installation degree of difficulty of waterproof ventilated membrane 7, in addition, the setting of limit ring board 16 can also cooperate the fixed waterproof ventilated membrane 7 of stabilizing of sealing plug 8, need not to set up extra glue and pastes waterproof ventilated membrane 7.

Of course, in order to prevent the position of the waterproof breathable membrane 7 from moving during installation, the waterproof breathable membrane 7 can be fixed on the limit ring plate 16 by gluing, and then the sealing plug 8 is assembled, and the waterproof breathable membrane 7 is compressed by the sealing plug 8.

In the present embodiment, the base case 11 is press-formed with the second convex portion 15. The difficulty in manufacturing and mounting the second projection 15 can be reduced by press-molding the second projection 15 directly on the base case 11, and the strength of the connection position between the second projection 15 and the base case 11 molded in this manner is high, and the second projection 15 does not fall off from the base case 11. Of course, the second projection 15 may be separately manufactured and then fixed to a predetermined position of the base case 11 by welding or the like.

In addition, in order to ensure the sealing performance of the whole winding type lithium ion battery, the liquid injection hole is sealed through a sealing nail after the liquid injection is finished.

In an embodiment, the pole piece 22 of the winding type battery cell 2 is provided with a tab 21 at or near the center of the winding type battery cell 2, and the tab 21 extends to the outside of the winding type battery cell 2. The pole lug 21 is led out to the outside of the winding type battery cell 2 from the central position of the winding type battery cell 2 or the position close to the central position, so that the pulling acting force of the deformation of the winding type battery cell 2 on the pole piece 22 can be effectively reduced, the pole piece 22 is not easy to break, and the service life of the pole piece 22 is prolonged.

The central position of the winding type battery cell 2 is the position located at the winding starting end in the winding process, the winding of the winding type battery cell 2 is taken as the winding center, namely, the position or the central position on the positive plate 221 close to the winding center of the winding type battery cell 2 is provided with the positive tab 211, the position or the central position on the negative plate 222 close to the winding center of the winding type battery cell 2 is provided with the negative tab 212, and after the positive plate 221, the negative plate 222 and the diaphragm 25 are overlapped, the winding is started from one end provided with the positive tab 211 and the negative tab 212 to form the winding type battery cell 2. Positive tab 211 and negative tab 212 are respectively led out from the same end of winding type cell 2 in the axial direction.

In an embodiment, as shown in fig. 7 and 8, the pole piece 22 of the winding type battery cell 2 is in a long strip shape, when one pole tab 21 is disposed on the pole piece 22, the pole tab 21 is disposed at a central position in a length direction of the pole piece 22, when at least two pole tabs 21 are disposed on the pole piece 22, the at least two pole tabs 21 are disposed at intervals along the length direction of the pole piece 22, and the pole tab 21 extends to the outside of the winding type battery cell 2. By arranging a single tab 21 at the center of the pole piece 22 of the winding type battery cell 2 in the length direction, or arranging a plurality of tabs 21 on the pole piece 22 at intervals, the winding type battery can meet the requirements of quick charge and high-rate discharge.

In an embodiment, as shown in fig. 7, the positive electrode sheet 221 and the negative electrode sheet 222 of the pole piece 22 of the winding type battery cell 2 are similar in shape and both have a long strip shape.

In an embodiment, when only one positive tab 211 is disposed on the positive tab 221 and only one negative tab 212 is disposed on the negative tab 222, the positive tab 211 is located at the center of the positive tab 221 in the length direction and extends toward one end of the winding type cell 2, the negative tab 212 is located at the center of the negative tab 222 in the length direction and extends toward one end of the winding type cell 2, and the extending directions of the positive tab 211 and the negative tab 212 may be the same or opposite.

Of course, the number of the tabs 21 on the pole piece 22 is not limited to one, and may be two or more, and when two or more tabs 21 are provided on the pole piece 22, one tab 21 is provided at the center position in the longitudinal direction of the pole piece 22, and the remaining tabs 21 are provided at one side or both sides of the tab 21 at intervals. As shown in fig. 8, three tabs 21 are provided on each pole piece 22 as an example, one tab 21 is provided at the center of the pole piece 22 in the length direction, and the remaining two tabs 21 are symmetrically provided along the center of the pole piece 22 in the length direction.

In other embodiments, if at least two tabs 21 are provided on the pole piece 22, the tabs 21 may also be provided at the ends of the pole piece 22 in the length direction.

The embodiment of the present invention further provides a manufacturing method of a wound lithium ion battery, which is used for manufacturing the wound lithium ion battery according to any of the above embodiments, and includes assembling a base 31 and a metal terminal 32, pouring an adhesive layer 33 between the base 31 and the metal terminal 32, curing the adhesive layer 33 to assemble the base 31 and the metal terminal 32 into a terminal assembly 3, welding the terminal assembly 3 in a lead-out hole 112 of a base shell 11, placing a wound electric core 2 in the base shell 11, respectively welding a tab 21 of the wound electric core 2 to the metal terminal 32 and the base shell 11, then assembling a cover 12 and the base shell 11, and finally injecting liquid into the housing 1.

In the description herein, it is to be understood that the terms "upper" and the like are based on the orientation or positional relationship shown in the drawings, which are for convenience of description and simplicity of operation, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present invention.

In the description herein, references to the term "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 in connection with 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 inventive effort, which would fall within the scope of the present invention.

Claims

1. A coiled lithium ion battery is characterized by comprising a shell and a coiled battery cell arranged in the shell, wherein the shell is a metal shell, a leading-out hole is formed in the shell, a terminal assembly is fixedly arranged in the leading-out hole and comprises a base and a metal terminal, a mounting hole is formed in the base in a penetrating manner, the metal terminal is inserted into the mounting hole, two ends of the metal terminal are respectively positioned outside the mounting hole, the metal terminal is connected with the hole wall of the mounting hole through a solidified viscose layer, one tab of the coiled battery cell is connected with one end of the metal terminal, which is positioned in the shell, and the other tab is connected with the inner wall of the shell;

2. The coiled lithium ion battery of claim 1, wherein the base comprises a seat plate, a first protrusion is protruded from one side of the seat plate, the mounting hole is opened on the seat plate and penetrates through the first protrusion, the first protrusion is in plug-in fit with the lead-out hole, and the seat plate abuts against the inner wall of the housing or the outer wall of the housing.

3. The coiled lithium ion battery of claim 1, wherein the metal terminal has at least a bonding area bonded to the adhesive layer;

4. The coiled lithium ion battery of claim 1, wherein a reinforcing plate is fixed to the casing, the reinforcing plate is spaced from the lead-out hole, and the connection position of the tab and the casing is located at the reinforcing plate.

5. The coiled lithium ion battery of claim 1, wherein the housing is provided with a chemical pore, the chemical pore is spaced from the lead-out hole, and a waterproof breathable film is arranged in the chemical pore.

6. The coiled lithium ion battery of claim 1, wherein the casing comprises a base casing and a cover, the base casing is a casing structure with one open end and one closed end, the open end of the base casing is located on one side surface of the casing in the thickness direction, and the cover blocks the open end of the base casing.

7. The coiled lithium ion battery of claim 6, wherein the terminal assembly is mounted on a side of the base housing that is perpendicular to the cover.

8. The coiled lithium ion battery of claim 1, wherein the casing is a cylindrical shell, an opening is formed in an arc-shaped side surface of the casing, and the opening is sealed by a cover body.

9. A coiled lithium-ion battery according to claim 1, wherein a first insulating plate is provided between the metal terminal and the inner wall of the case.

10. The wound lithium ion battery according to any one of claims 1 to 9, wherein the pole piece of the wound cell comprises a current collector and an active material coated on the current collector, the current collector has an extension portion extending out of the active material along a radial direction of the wound cell, the extension portion is folded and then partially overlapped, the extension portion and the pole piece are arranged at an included angle, and the extension portion forms the tab; or the like, or, alternatively,

11. The wound lithium ion battery of any one of claims 1 to 9, wherein the wound battery cell comprises a positive plate, a negative plate, and a separator disposed between the positive plate and the negative plate, the separator has a separation part extending to both ends of the negative plate along an axial direction of the wound battery cell, and the separation part is used for separating a tab of the wound battery cell from an end face of the wound battery cell; or the like, or, alternatively,