Wound Lithium-ion Battery

Abstract

The present invention discloses a wound lithium ion battery, comprising a metal shell and a wound cell, wherein a lead-out hole is provided on the shell, wherein a terminal assembly is fixedly arranged inside the shell, wherein the terminal assembly comprises a base and a metal terminal, wherein the metal terminal is inserted into the mounting hole of the base, wherein both ends of the metal terminal are respectively located outside the mounting hole, and the two are connected by a cured adhesive layer, wherein the pole ear of the wound cell comprises a positive pole ear and a negative pole ear, wherein one of the positive pole ear and the negative pole ear is connected to one end of the metal terminal located inside the shell, and the other is connected to the inner wall of the shell; wherein the pole piece of the wound cell is in the shape of an elongated strip, wherein when one pole ear is provided on the pole piece, the pole ear is provided at the center position in the length direction of the pole piece, and when at least two pole ears are provided on the pole piece, at least two pole ears are provided at intervals along the length direction of the pole piece, and the pole ear extends to the outside of the wound cell. The wound lithium ion battery of the present invention has a good sealing effect, a large volume energy density of the battery, and can achieve fast charging and high rate discharge performance.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a wound lithium-ion battery. Background Art

[0002] Due to the limitation of packaging technology, the sealing area of ​​the lead-out part of the positive and negative terminals of the soft-pack battery occupies the internal and external space of the battery, resulting in a reduction in the volume energy density of the battery, and the terminal lead-out structure is complex, which increases the difficulty of assembly and sealing. In addition, due to the protruding structure of the lead-out part of the positive and negative terminals of the soft-pack battery, it is difficult to assemble multiple single soft-pack cells into a battery pack or install circuit protection devices. Summary of the invention

[0003] An object of an embodiment of the present invention is to provide a wound lithium-ion battery with a simple structure, easy assembly, good sealing effect, and high volume energy density.

[0004] Another object of an embodiment of the present invention is to provide a wound lithium-ion battery that can achieve fast charging and high-rate discharge performance.

[0005] To achieve this purpose, the embodiment of the present invention adopts the following technical solutions:

[0006] Provided is a wound lithium-ion battery, comprising a shell and a wound battery cell arranged in the shell, wherein the shell is a metal shell, a lead-out hole is provided on the shell, a terminal assembly is fixedly provided in the lead-out hole, the terminal assembly comprises a base and a metal terminal, a mounting hole is provided through the base, 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 to the hole wall of the mounting hole through a cured adhesive layer, the pole lugs of the wound battery cell comprise a positive pole lug and a negative pole lug, one of the positive pole lug and the negative pole lug is connected to one end of the metal terminal located in the shell, and the other of the positive pole lug and the negative pole lug is connected to the inner wall of the shell;

[0007] The pole piece of the wound battery cell is in the shape of an elongated strip. When one pole ear is provided on the pole piece, the pole ear is provided at the center position of the length direction of the pole piece. When at least two pole ears are provided on the pole piece, at least two pole ears are provided at intervals along the length direction of the pole piece, and the pole ears extend to the outside of the wound battery cell.

[0008] As a preferred solution for a wound lithium-ion battery, the base includes a seat plate, a first protrusion is protruding from one side of the seat plate, the mounting hole is opened on the seat plate and passes through the first protrusion, the first protrusion is plugged into and matched with the lead-out hole, and the seat plate abuts against the inner wall of the outer shell or the outer wall of the outer shell.

[0009] As a preferred solution of the wound lithium-ion battery, the metal terminal has at least a bonding area bonded to the adhesive layer;

[0010] The bonding area is provided with a rough layer; or, the bonding area is provided with a plurality of bonding protrusions protruding from the surface of the metal terminal.

[0011] As a preferred solution of the wound lithium-ion battery, a reinforcing plate is fixed on the shell, the reinforcing plate is spaced apart from the lead-out hole, and the connection position between the electrode tab and the shell is located at the reinforcing plate.

[0012] As a preferred solution of the wound lithium-ion battery, a formation hole is provided on the shell, the formation hole is spaced apart from the lead-out hole, and a waterproof and breathable membrane is provided in the formation hole.

[0013] As a preferred solution for a 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 in the thickness direction of the outer shell, and the cover body blocks the open end of the base shell.

[0014] As a preferred solution for the wound lithium-ion battery, the terminal assembly is mounted on a side of the base shell that is perpendicular to the cover body.

[0015] As a preferred solution of the wound lithium-ion battery, the shell is a cylindrical shell, an opening is opened on the arc-shaped side of the shell, and the opening is sealed by a cover.

[0016] As a preferred solution of the wound lithium-ion battery, a first insulating plate is provided between the metal terminal and the inner wall of the shell.

[0017] As a preferred solution of a wound lithium-ion battery, the pole piece of the wound battery cell includes a current collector and an active material coated on the current collector, the current collector has an extension portion extending outside the active material along the radial direction of the wound battery cell, the extension portion is partially overlapped after being bent, the extension portion is arranged at an angle with the pole piece, and the extension portion forms the pole ear; or,

[0018] The pole piece of the wound battery cell comprises a current collector and an active material coated on the current collector, the current collector has an extension portion extending outside the active material along the axial direction of the wound battery cell, and the extension portion forms the pole lug.

[0019] As a preferred solution of a wound lithium-ion battery, the wound battery cell comprises a positive electrode sheet, a negative electrode sheet and a separator arranged between the positive electrode sheet and the negative electrode sheet, the separator has a separator extending along the axis direction of the wound battery cell to both ends of the negative electrode sheet, and the separator is used to isolate the tab of the wound battery cell from the end face of the wound battery cell; or,

[0020] An insulating member is arranged between the pole tab and the end surface of the wound battery core.

[0021] The beneficial effects of the embodiments of the present invention are as follows: by connecting one pole ear of the wound battery cell to the metal terminal of the terminal assembly and the other pole ear to the outer shell, only one sealing structure can be set on the outer shell, and the sealing structure of the integrated terminal assembly is simple and occupies less space in the outer shell, so that the volume energy density of the wound lithium-ion battery is large. In addition, the integrated terminal assembly can also effectively reduce the difficulty of installation, and the cured adhesive layer can improve the sealing and fixing effects; by setting a single pole ear at the center position of the length direction of the pole piece of the wound battery cell, or arranging multiple pole ears at intervals on the pole piece, the wound bean-type battery can meet the requirements of fast charging and high-rate discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention is further described in detail below based on the accompanying drawings and embodiments.

[0023] Figure 1 It is a three-dimensional schematic diagram of a wound lithium-ion battery from a first viewing angle according to an embodiment of the present invention (the terminal assembly portion is shown in an exploded state).

[0024] Figure 2 It is a perspective schematic diagram of a wound lithium-ion battery from a second viewing angle according to an embodiment of the present invention (the terminal assembly portion is shown in an exploded state).

[0025] Figure 3 FIG. 4 is a cross-sectional schematic diagram of a wound lithium-ion battery according to an embodiment of the present invention.

[0026] Figure 4 FIG. 1 is a top view of a wound lithium-ion battery according to an embodiment of the present invention (the cover is not shown).

[0027] Figure 5 FIG. 4 is a cross-sectional schematic diagram of a wound lithium-ion battery according to another embodiment of the present invention.

[0028] Figure 6 FIG. 4 is a cross-sectional schematic diagram of a wound lithium-ion battery according to another embodiment of the present invention.

[0029] Figure 7 It is a schematic diagram of assembling a pole piece and a pole ear in an unfolded state according to an embodiment of the present invention.

[0030] Figure 8 It is a schematic diagram of assembling a pole piece and a pole ear in an unfolded state according to another embodiment of the present invention.

[0031] Fig. 9 Schematic cross-sectional view of a wound battery cell according to an embodiment of the present invention.

[0032] Fig.10 It is a schematic diagram of the structure of a pole piece and a pole ear according to an embodiment of the present invention.

[0033] Fig.11 It is a schematic structural diagram of a pole piece and a pole ear according to another embodiment of the present invention.

[0034] Fig.12 It is a partial cross-sectional view of a base shell according to an embodiment of the present invention.

[0035] Fig.13 A partial cross-sectional view of a base shell according to another embodiment of the present invention.

[0036] Fig.14 It is a schematic front view of a first insulating plate according to an embodiment of the present invention.

[0037] Fig.15 FIG. 4 is a schematic side view of a first insulating plate according to an embodiment of the present invention.

[0038] In the figure:

[0039] 1. Shell; 11. Base shell; 111. Mounting part; 112. Lead-out hole; 12. Cover body; 13. Forming hole; 131. Step surface; 14. Sealing plate; 15. Second convex part; 16. Limiting ring plate;

[0040] 2. wound cell; 21. pole ear; 211. positive pole ear; 212. negative pole ear; 22. pole piece; 221. positive pole piece; 222. negative pole piece; 23. extension part; 231. overlapping position; 24. reinforcement member; 25. diaphragm; 251. isolation part;

[0041] 3. Terminal assembly; 31. Base; 311. Seat plate; 312. First protrusion; 313. Mounting hole; 32. Metal terminal; 33. Adhesive layer;

[0042] 4. first insulating plate; 41. first plate body; 42. second plate body;

[0043] 5. Reinforcement plate;

[0044] 6. second insulating plate; 61. notch;

[0045] 7. Waterproof and breathable membrane;

[0046] 8. Sealing plug; 81. Air vent; 82. Plug body; 83. Third protrusion. DETAILED DESCRIPTION

[0047] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0048] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0050] Reference Figures 1 to 6As shown, the wound lithium-ion battery disclosed in the present invention includes a shell 1 and a wound battery cell 2 arranged in the shell 1, the shell 1 is a metal shell 1, a lead-out hole 112 is opened on the shell 1, a terminal assembly 3 is fixedly arranged in the lead-out hole 112, the terminal assembly 3 includes a base 31 and a metal terminal 32, a mounting hole 313 is opened through the base 31, the metal terminal 32 is inserted into the mounting hole 313, the two ends of the metal terminal 32 are respectively located outside the mounting hole 313, the metal terminal 32 is connected to the hole wall of the mounting hole 313 by a cured adhesive layer 33, one pole ear 21 of the wound battery cell 2 is connected to one end of the metal terminal 32 located in the shell 1, and the other pole ear 21 is connected to the inner wall of the shell 1. By connecting one pole ear 21 of the wound battery cell 2 to the metal terminal 32 of the terminal assembly 3 and the other pole ear 21 to the outer shell 1, only one sealing structure can be set on the outer shell 1, and the sealing structure of the integrated terminal assembly 3 is simple and occupies less space in the outer shell 1, so that the volume energy density of the wound lithium-ion battery is increased. In addition, the integrated terminal assembly 3 can also effectively reduce the difficulty of installation, and the cured adhesive layer 33 can improve the sealing and fixing effects.

[0051] In other embodiments, the base 31 and the metal terminal 32 are not limited to being connected by the cured adhesive layer 33. A sealing ring may be provided on the inner wall of the mounting hole 313 of the base 31. The sealing ring is sleeved outside the metal terminal 32, and the connection, sealing and insulation between the base 31 and the metal terminal 32 are achieved by the sealing ring. In order to further prevent the position of the sealing ring from moving, a circle of mounting grooves is provided in the mounting hole 313, and the sealing ring is clamped in the mounting groove.

[0052] The outer shell 1 is made of metal material with high hardness, which can ensure that the appearance of the entire wound lithium-ion battery remains unchanged and can effectively prevent the outer shell 1 from being deformed due to inflation in the battery.

[0053] The metal material here can be a single metal material or an alloy material. In this embodiment, the metal material is stainless steel.

[0054] In addition, under the premise of ensuring mechanical strength, metal foil materials, such as steel foil, can be further used, so as to further reduce the weight of the battery.

[0055] The wound battery core 2 can be in a square column, a cylindrical column, an elliptical column, etc., and its shape corresponds to the shape of the housing 1 .

[0056] In this embodiment, if Figure 1 and 2As shown, the housing 1 is rectangular, and the terminal assembly 3 is arranged at one end of the housing 1 in the length direction, that is, the housing 1 is a flat square structure, and correspondingly, the wound battery core 2 is a square columnar structure.

[0057] Specifically, the housing 1 includes a base housing 11 and a cover 12, wherein the base housing 11 is a shell structure with one end open and the other end sealed, the open end of the base housing 11 is located on one of the side surfaces in the thickness direction of the housing 1, the cover 12 blocks the open end of the base housing 11, and the terminal assembly 3 is mounted on the side surface of the base housing 11 perpendicular to the cover 12. The housing 1 with this structure is more convenient for placing the wound battery cell 2, because the opening of the base housing 11 is located on one of the side surfaces in the thickness direction of the housing 1, which means that the size of the opening can be made very large, and the wound battery cell 2 is more convenient to place, with lower difficulty, and can increase the housing insertion ratio.

[0058] The thickness direction of the shell 1 in the embodiment of the present invention refers to the vertical direction of the two parallel sides of the flat structure shell 1 with larger areas, that is, the thickness of the shell 1 is the distance between the two parallel sides of the flat structure shell 1 with larger areas, and one side in this thickness direction is the side of the shell 1 with larger area. The size of the opening end set on this side is larger, which is more convenient for placing the wound battery cell 2.

[0059] The cover body 12 is in the shape of a flat plate and is fixedly connected to the base shell 11 by welding. After the cover body 12 is welded in place, the sealing end of the base shell 11 is blocked, and a closed cavity is formed inside the outer shell 1.

[0060] Optionally, the opening end of the base shell 11 extends toward the outside of the housing 1 with a mounting portion 111, and the mounting portion 111 is connected to the cover 12. By providing the mounting portion 111, the difficulty of assembling the cover 12 and the base shell 11 can be reduced, and the welding mode is changed from a butt joint mode to a corner joint mode, which greatly reduces the welding difficulty and improves the welding speed. In addition, the sealing can be improved to effectively prevent the leakage of the electrolyte. At the same time, after the welding is completed, the redundant mounting portion 111 can be cut and removed, so that the volume of the battery can be further reduced.

[0061] In other embodiments, the cover body 12 is not limited to being a flat plate, but can also be configured to be consistent with the structure of the base shell 11, that is, the cover body 12 is also a shell structure with one end open and the other end sealed, and the open end of the cover body 12 and the open end of the base shell 11 are docked or sleeved to achieve sealing. In this case, the terminal assembly 3 can be set on the base shell 11 or on the cover body 12.

[0062] In addition, when the shell 1 is cylindrical, an opening is provided on the arc-shaped side of the shell 1, and the opening is blocked by the cover body 12. At this time, the cover body 12 is an arc-shaped plate structure, and the terminal assembly 3 is installed on one of the end faces of the cylindrical shell 1.

[0063] In one embodiment, the base 31 of the terminal assembly 3 includes a seat plate 311, a first protrusion 312 is protruding from one side of the seat plate 311, the mounting hole 313 is opened on the seat plate 311 and passes through the first protrusion 312, the first protrusion 312 is plugged and matched with the lead-out hole 112, and the seat plate 311 abuts against the inner wall of the base shell 11 or the outer wall of the base shell 11. The cooperation between the first protrusion 312 and the seat plate 311 can reduce the difficulty of assembling the terminal assembly 3, the seat plate 311 can limit the plug-in position of the terminal assembly 3, the first protrusion 312 is matched with the lead-out hole 112, and finally the terminal assembly 3 is welded to the base shell 11 to achieve a fixed connection between the terminal assembly 3 and the base shell 11.

[0064] In this embodiment, the seat plate 311 abuts against the outer wall of the base shell 11 , and the outer periphery of the seat plate 311 is welded to the base shell 11 by laser welding or resistance welding to achieve sealing and fixing.

[0065] like Figure 1 , Figure 2 , Fig.14 and Fig.15 If one end of the metal terminal 32 inside the base shell 11 is too long, it needs to be bent and fitted to the inner wall of the base shell 11. In order to prevent electrical conduction between the metal terminal 32 and the base shell 11, a first insulating plate 4 is provided between the metal terminal 32 and the inner wall of the base shell 11.

[0066] The first insulating plate 4 can be fixed to the inner wall of the base shell 11 by bonding, or by other fixing methods such as snap-fit ​​connection. The first insulating plate 4 is L-shaped, and includes a first plate body 41 and a second plate body 42 connected vertically. The first plate body 41 is inserted between the inner wall of the base shell 11 and the metal terminal 32 for insulation isolation, and the second plate body 42 is located at the end surface of the open end of the base shell 11. The L-shaped first insulating plate 4 can be positioned during installation to reduce the difficulty of installation.

[0067] In order to increase the connection stability and sealing between the metal terminal 32 and the base 31, a rough layer is provided in the bonding area between the metal terminal 32 and the adhesive layer 33, or a plurality of bonding protrusions protruding from the surface of the metal terminal 32 are provided. The rough layer or bonding protrusions are used to enhance the bonding strength between the metal terminal 32 and the adhesive layer 33, thereby improving the connection stability and sealing between the metal terminal 32 and the base 31. Of course, the entire surface of the metal terminal 32 may also be provided with a rough layer or distributed with bonding protrusions.

[0068] In one embodiment, if Figures 1 to 4As shown, a reinforcing plate 5 is fixed on the base shell 11, the reinforcing plate 5 is spaced from the lead-out hole 112, and the connection position between the pole lug 21 and the base shell 11 is located at the reinforcing plate 5. The provision of the reinforcing plate 5 can increase the thickness of the welding position between the base shell 11 and the pole lug 21, and prevent the base shell 11 from being punctured when the pole lug 21 and the base shell 11 are welded.

[0069] The reinforcing plate 5 can be arranged on the inner wall of the base shell 11 or on the outer wall of the base shell 11. In this embodiment, the reinforcing plate 5 is located on the outer wall of the base shell 11.

[0070] In addition, in order to further prevent the metal sheet outside the housing 1 from contacting the housing 1 , an insulating glue may be applied on the seat plate 311 outside the housing 1 or an insulating member may be provided.

[0071] The pole ear 21 of the wound battery cell 2 includes a positive pole ear 211 and a negative pole ear 212, wherein the negative pole ear 212 is welded to the metal terminal 32 of the terminal assembly 3, and the positive pole ear 211 is welded to the inner wall of the base shell 11, and the welding position is exactly where the reinforcing plate 5 is located. Of course, the positive pole ear 211 can also be welded to the metal terminal 32 of the terminal assembly 3, and the negative pole ear 212 can be welded to the inner wall of the base shell 11, and the welding position is exactly where the reinforcing plate 5 is located.

[0072] In this embodiment, the positive electrode tab 211 and the negative electrode tab 212 are both led out from the same end of the wound battery cell 2 , and the side of the base shell 11 where the terminal assembly 3 is provided and the side where the base shell 11 and the positive electrode tab 211 are welded are the same side.

[0073] In other embodiments, the positive electrode ear 211 and the negative electrode ear 212 are not limited to being led out at the same end of the wound battery cell 2, but can also be respectively arranged at the two ends of the wound battery cell 2. In this case, the reinforcing plate 5 and the terminal assembly 3 are respectively arranged on the side surfaces at the two ends of the length direction of the base shell 11.

[0074] In one embodiment, referring to Fig.10 and Fig.11 The pole piece 22 of the wound 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 wound battery cell 2. The extension portion 23 is partially overlapped after being bent. The extension portion 23 is arranged at an angle with the pole piece 22, and the extension portion 23 forms the pole ear 21. By extending the extension portion 23 of the current collector of the pole piece 22 to the outside of the active material and bending it to directly form the pole ear 21, the process of welding the pole ear 21 is omitted, the production efficiency is improved, and the internal resistance of the wound battery cell 2 is reduced. At the same time, the integrally formed pole ear 21 and pole piece 22 have higher strength and are not easy to separate.

[0075] Of course, the current collector has an extension portion 23 extending outside the active material along the axial direction of the wound battery cell 2. The extension portion 23 does not need to be bent to directly form the pole ear 21. Specifically, this extension portion 23 is arranged in the length direction of the positive / negative electrode sheet in a long strip shape. When winding along the length direction of the positive / negative electrode sheet in a long strip shape, the extension portion 23 is directly formed at both ends of the axial direction of the wound battery cell 2, and then the extension portion 23 of the positive electrode sheet 221 and the extension portion 23 of the negative electrode sheet 222 are respectively welded to form the positive / negative pole ear.

[0076] Preferably, a reinforcement member 24 is provided at the overlapped position 231 of the extension 23. By providing an additional reinforcement member 24 at the overlapped position 231 of the extension 23, the reinforcement member 24 can strengthen the strength of the bent overlapped position 231, effectively prevent the extension 23 from being broken after being bent, protect the integrity of the tab 21, and also strengthen the overall strength of the tab 21.

[0077] The bending angle of the extension part 23 is flexibly adjusted according to the requirements of the wound battery cell 2 during packaging. Specifically, the extension part 23 is bent at the position connected to the end of the pole piece 22 as a fulcrum, and the first angle α is bent, wherein the first angle α is 90°. This angle can make it easier for the extension part 23 to be led out from both ends of the wound battery cell 2, shorten the length of the pole ear 21, and reduce the manufacturing cost. Of course, the bending angle of the extension part 23 is not limited to 90°, and the first angle α can also be set to 30°, 45°, 100° or 120°, etc. according to needs.

[0078] like Fig.10 As shown, in a preferred embodiment of the present invention, the reinforcing member 24 is a tape wrapped around the outside of the overlapping position 231 of the extension 23. The reinforcing member 24 is set as a tape. On the one hand, it can buffer the overlapping position 231 of the extension 23 after bending, and can alleviate the stress of the extension 23 at the bending position to a certain extent, effectively reducing the phenomenon of the extension 23 breaking at the overlapping position 231 and causing the pole ear 21 and the pole piece 22 to separate. On the other hand, the tape is used to protect and shape the structure of the overlapping position 231 of the extension 23, preventing the pole ear 21 from being deformed at the overlapping position 231 of the extension 23 after long-term use, thereby affecting the normal use of the wound battery cell 2. In order to further enhance the protective effect of the tape on the extension 23, multiple layers of tape can be wrapped around the overlapping position 231.

[0079] like Fig.11As shown, in another preferred embodiment of the present invention, the reinforcing member 24 is a double-sided adhesive tape, and a first overlapping surface and a second overlapping surface that are in contact with each other are provided on the extension portion 23 and located at the overlapping position 231, and the double-sided adhesive tape is provided between the first overlapping surface and the second overlapping surface. The provision of the double-sided adhesive tape can effectively prevent the first overlapping surface and the second overlapping 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.

[0080] In addition, the extension portion 23 can be bent multiple times at the same position to increase the thickness of the overlapping position 231 , thereby improving the strength of the pole piece 22 .

[0081] Of course, the pole ear 21 is not limited to being integrally formed with the current collector of the pole piece 22, but can also be separately formed, with a reserved position on the current collector of the pole piece 22 where no active material is coated to form an empty foil area, one end of the pole ear 21 is welded to the empty foil area, and the other end is welded to the metal terminal 32 of the terminal assembly 3 or the outer shell 1.

[0082] In one embodiment, if Fig. 9 As shown, a diaphragm 25 is provided between the positive electrode sheet 221 and the negative electrode sheet 222 of the wound battery cell 2, and the diaphragm 25 has a separation portion 251 extending along the axial direction of the wound battery cell 2 to the two ends of the negative electrode sheet 222, and the separation portion 251 is used to separate the pole ear 21 of the wound battery cell 2 from the end face of the wound battery cell 2. The provision of the separation portion 251 can effectively prevent the pole ear 21 from making electrical contact with the two ends of the wound battery cell 2 in the vertical direction, and there is no need to additionally provide an insulating gasket on the end face of the wound battery cell 2, which reduces the difficulty and cost of preparing the wound lithium-ion battery, improves the production efficiency, and at the same time, there is no need to change the preparation process and equipment of the existing battery, which is conducive to the large-scale production of the wound lithium-ion battery, and has good insulation.

[0083] In this embodiment, the length of the isolating portion 251 extending from the end surface of the wound battery cell 2 is not less than 0.75 mm. This design can ensure that the end surface of the wound battery cell 2 formed by winding the positive electrode sheet 221, the negative electrode sheet 222 and the separator 25 has a sufficient length of the isolating portion 251 to insulate the tab 21 and ensure the insulation effect.

[0084] Of course, the isolation portion 251 is not limited to isolating the end surface of the electrode tab 21 and the wound battery cell 2. Figures 1 to 6 As shown, an additional second insulating plate 6 may be provided to isolate the electrode tab 21 from the end surface of the wound battery cell 2 .

[0085] Specifically, Figure 1 and Figure 2As shown, the second insulating plate 6 is in the shape of a flat plate, and a notch 61 is provided on it for the negative electrode ear 212 to pass through. Of course, the number of notches 61 is not limited to one, and can also be two, that is, one notch 61 is provided for each of the positive electrode ear 211 and the negative electrode ear 212, and the two notches 61 are provided at intervals. Of course, the structure for the electrode ear 21 to pass through is not limited to the notch 61, and a through hole can also be provided for the corresponding electrode ear 21 to pass through. In addition, the design of the notch 61 is also conducive to the penetration of the electrolyte into the wound battery cell 2.

[0086] In addition, generally, since the current collector of the positive electrode sheet 221 is aluminum foil, and the current collector of the negative electrode sheet 222 is copper foil, the material of the positive electrode tab 211 is aluminum foil, and the material of the negative electrode tab 212 is copper foil. Both aluminum foil and copper foil are softer than the existing tab material aluminum sheet (strip) or nickel sheet (strip), so that the separator 251 is not easily punctured by the tab 21 when attached to the end face of the wound battery cell 2.

[0087] In order to further improve the safety of the wound lithium-ion battery, a separator 25 having high temperature resistance (130-150° C.) and / or high mechanical strength, such as an aramid separator, may be used.

[0088] The above-mentioned wound lithium-ion battery is a rechargeable battery.

[0089] Reference Figure 1 , Fig.12 and Fig.13 As shown, the outer side of the base shell 11 mentioned in the embodiment of the present invention refers to: after the base shell 11 and the cover body 12 are assembled, the side of the base shell 11 is away from the wound battery core 2, that is, the side that the operator can intuitively observe or operate.

[0090] The base shell 11 of the embodiment of the present invention is provided with a formation hole 13, a waterproof breathable membrane 7 is provided in the formation hole 13, and a sealing mechanism for blocking the formation hole 13 after the formation operation is completed is also provided on the base shell 11. By arranging the waterproof breathable membrane 7 in the formation hole 13, the wound lithium ion battery can directly use the formation hole 13 to perform the formation operation during the formation operation, and the characteristic of the waterproof breathable membrane 7 is that only gas can pass through, and moisture cannot pass through, so external moisture cannot pass through the waterproof breathable membrane 7 to enter the inside of the wound lithium ion battery, ensuring the excellent performance of the wound lithium ion battery after the formation operation, and at the same time, the requirement for environmental drying can be reduced, and the formation operation can be performed under a conventional environment, thereby reducing the difficulty of operation and energy consumption; by arranging the sealing mechanism, the formation hole 13 can be blocked after the formation is completed, so that the entire wound lithium ion battery is in a sealed state.

[0091] Preferably, the waterproof breathable membrane 7 is a polytetrafluoroethylene membrane (ie, E-PTFE membrane) or a polyurethane membrane (ie, PU membrane).

[0092] In one embodiment, if Fig.12 As shown, the formation hole 13 and the injection hole on the shell 1 are combined into one, and the waterproof breathable membrane 7 is installed in the formation hole 13 after the injection is completed. By combining the formation hole 13 and the injection hole into one, the number of holes opened on the base shell 11 can be reduced, thereby reducing the difficulty of operation, which can meet the injection requirements and cooperate to complete the formation operation, thereby simplifying the structure of the base shell 11.

[0093] In this embodiment, the formation hole 13 is a stepped hole, which includes a first hole and a second hole that are connected, the size of the first hole is larger than the size of the second hole, and a stepped surface 131 is formed at the connection between the first hole and the second hole, and the waterproof breathable membrane 7 is fixed on the stepped surface 131. By providing the stepped surface 131, the installation and fixation of the waterproof breathable membrane 7 can be facilitated.

[0094] Specifically, the waterproof breathable membrane 7 is bonded to the step surface 131. The bonding method is simple to operate, can achieve fixation without setting additional fasteners and other structures, and is also very convenient to disassemble and replace.

[0095] Furthermore, the first hole is adjacent to the outer side of the base shell 11. Placing the larger first hole adjacent to the outer side of the base shell 11 can reduce the difficulty of installing the waterproof breathable membrane 7.

[0096] In other embodiments, the formation hole 13 may also be configured as a through hole, a tapered hole or other hole types.

[0097] The sealing mechanism is a sealing plate 14, which is fixed to the outside of the base shell 11 and blocks the formation hole 13. The setting of the sealing plate 14 can seal the formation hole 13 after the injection and formation, thereby ensuring the overall sealing of the entire wound lithium-ion battery. Preferably, the sealing plate 14 is welded to the outside of the base shell 11.

[0098] In one embodiment, if Fig.13 As shown, the formation hole 13 and the injection hole are not limited to being combined into one, and the formation hole 13 can also be separately provided on the base shell 11, and the formation hole 13 and the injection hole are spaced apart from each other on the base shell 11.

[0099] In this embodiment, a second protrusion 15 is provided on the base shell 11 and protrudes toward the outside thereof, the formation hole 13 is opened on the second protrusion 15 and passes through the second protrusion 15 and the base shell 11, and the sealing mechanism is a sealing plug 8, and the sealing plug 8 is at least partially inserted into the formation hole 13 and abuts against the waterproof and breathable membrane 7.

[0100] Preferably, the sealing plug 8 has a vent hole 81 formed therethrough, and the sealing plug 8 can be deformed by external extrusion to seal the vent hole 81. Extruding the sealing plug 8 to deform and seal the vent hole 81 can reduce the difficulty of the sealing operation, and no welding or other operations are required on the base shell 11.

[0101] Specifically, the sealing plug 8 is made of PFA material (perfluoroalkoxy resin). The sealing plug 8 made of this material can be deformed by external mechanical extrusion, and will not automatically recover after deformation, which can improve the sealing effect and effectively reduce the difficulty of sealing. In this embodiment, the protruding second convex portion 15 is more convenient for the extrusion operation of the sealing plug 8. During the specific operation, the second convex portion 15 is pressed to deform the second convex portion 15. The deformed second convex portion 15 will drive the sealing plug 8 inside it to deform, thereby blocking the air vent 81 and achieving the sealing of the lithium-ion battery.

[0102] The sealing plug 8 can be installed in the formation hole 13 from the outside of the base shell 11 or from the inside of the base shell 11 . In this embodiment, the sealing plug 8 is pre-installed in the formation hole 13 from the inside of the base shell 11 .

[0103] Specifically, the sealing plug 8 includes a plug body 82 and a third protrusion 83 protruding from a side of the plug body 82, the air vent 81 is penetrated through the third protrusion 83, the air vent 81 penetrates the plug body 82, the third protrusion 83 is inserted into the formation hole 13 and abuts against the waterproof breathable membrane 7, and the plug body 82 abuts against the side of the base shell 11 away from the second protrusion 15.

[0104] The second protrusion 15 is located away from one end of the base shell 11 and is annularly provided with a limiting ring plate 16 in the forming hole 13, and the waterproof breathable membrane 7 is clamped between the limiting ring plate 16 and the sealing plug 8. The limiting ring plate 16 can provide a mounting plane for the waterproof breathable membrane 7, reducing the difficulty of installing the waterproof breathable membrane 7. In addition, the limiting ring plate 16 can also cooperate with the sealing plug 8 to fix and stabilize the waterproof breathable membrane 7, without the need to set additional glue to stick the waterproof breathable membrane 7.

[0105] Of course, in order to prevent the waterproof breathable membrane 7 from moving during installation, the waterproof breathable membrane 7 can be fixed to the limiting ring plate 16 by gluing, and then the sealing plug 8 is assembled to press the waterproof breathable membrane 7 with the sealing plug 8.

[0106] In this embodiment, the base shell 11 is stamped to form the second protrusion 15. By directly stamping the second protrusion 15 on the base shell 11, the difficulty of manufacturing and installing the second protrusion 15 can be reduced. In addition, the strength of the connection position between the second protrusion 15 and the base shell 11 formed in this way is high, and the second protrusion 15 will not fall off the base shell 11. Of course, the second protrusion 15 can also be manufactured separately and then fixed to the specified position of the base shell 11 by welding or other methods.

[0107] In addition, in order to ensure the sealing of the entire wound lithium-ion battery, the injection hole is sealed by a sealing pin after the injection is completed.

[0108] In one embodiment, the pole piece 22 of the wound battery cell 2 is provided with a pole ear 21 at or near the center of the wound battery cell 2, and the pole ear 21 extends to the outside of the wound battery cell 2. By leading the pole ear 21 from the center of the wound battery cell 2 or near the center to the outside of the wound battery cell 2, the pulling force of the deformation of the wound battery cell 2 on the pole piece 22 can be effectively reduced, so that the pole piece 22 is not easy to break, and the service life of the pole piece 22 is extended.

[0109] The center position of the wound cell 2 is the position at the starting end of the winding process, and the winding of the wound cell 2 is based on this as the winding center, that is, the positive electrode tab 211 is provided at the position or center position of the winding center of the wound cell 2 on the positive electrode sheet 221, and the negative electrode tab 212 is provided at the position or center position of the winding center of the wound cell 2 on the negative electrode sheet 222. After the positive electrode sheet 221, the negative electrode sheet 222 and the separator 25 are stacked, the wound cell 2 is formed from the end where the positive electrode tab 211 and the negative electrode tab 212 are provided. The positive electrode tab 211 and the negative electrode tab 212 are respectively led out from the same end of the axial direction of the wound cell 2.

[0110] In one embodiment, if Figure 7 and Figure 8 As shown, the pole piece 22 of the wound battery cell 2 is in the shape of a long strip. When one pole ear 21 is provided on the pole piece 22, the pole ear 21 is provided at the center of the length direction of the pole piece 22. When at least two pole ears 21 are provided on the pole piece 22, at least two pole ears 21 are provided at intervals along the length direction of the pole piece 22, and the pole ears 21 extend to the outside of the wound battery cell 2. By providing a single pole ear 21 at the center of the length direction of the pole piece 22 of the wound battery cell 2, or by providing multiple pole ears 21 at intervals on the pole piece 22, the wound battery can meet the requirements of fast charging and high-rate discharge.

[0111] In one embodiment, if Figure 7 As shown, the positive electrode sheet 221 and the negative electrode sheet 222 of the electrode sheet 22 of the wound battery cell 2 have similar shapes, both in the shape of long strips.

[0112] In one embodiment, when only one positive electrode ear 211 is provided on the positive electrode sheet 221 and only one negative electrode ear 212 is provided on the negative electrode sheet 222, the positive electrode ear 211 is located at the center of the length direction of the positive electrode sheet 221 and extends toward one end of the wound battery cell 2, and the negative electrode ear 212 is located at the center of the length direction of the negative electrode sheet 222 and extends toward one end of the wound battery cell 2. The extension directions of the positive electrode ear 211 and the negative electrode ear 212 may be the same or opposite.

[0113] Of course, the number of the pole lug 21 on the pole piece 22 is not limited to one, but may be two or more. When two or more pole lugs 21 are provided on the pole piece 22, one pole lug 21 is provided at the center of the length direction of the pole piece 22, and the remaining pole lugs 21 are provided at intervals on one side or both sides of the pole lug 21. Figure 8 As shown, taking the example of three pole ears 21 being arranged on each pole piece 22 , one pole ear 21 is arranged at the center position of the pole piece 22 in the length direction, and the remaining two pole ears 21 are symmetrically arranged along the center of the length direction of the pole piece 22 .

[0114] In other embodiments, if at least two pole tabs 21 are disposed on the pole piece 22 , the pole tabs 21 may also be disposed at the ends of the pole piece 22 in the length direction.

[0115] An embodiment of the present invention also provides a method for manufacturing a wound lithium-ion battery, which is used to manufacture a wound lithium-ion battery as described in any of the above embodiments, 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 so that the base 31 and the metal terminal 32 are assembled into a terminal assembly 3, welding the terminal assembly 3 into the lead-out hole 112 of the base shell 11, placing a wound battery cell 2 in the base shell 11, and welding the pole ear 21 of the wound battery cell 2 to the metal terminal 32 and the base shell 11 respectively, then assembling the cover body 12 and the base shell 11, and finally injecting liquid into the outer shell 1.

[0116] In the description of this article, it is necessary to understand that the term "upper" and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0117] In the description of this specification, the description of reference term "an embodiment" etc. means that the specific features, structures, materials or characteristics of the embodiment are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment.

[0118] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0119] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A wound lithium-ion battery, characterized in that: The invention comprises a shell and a wound battery cell arranged in the shell, wherein the shell is a metal shell, a lead-out hole is provided on the shell, a terminal assembly is fixedly provided in the lead-out hole, the terminal assembly comprises a base and a metal terminal, a mounting hole is provided through the base, 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 to the hole wall of the mounting hole through a cured adhesive layer, the pole ear of the wound battery cell comprises a positive pole ear and a negative pole ear, one of the positive pole ear and the negative pole ear is connected to one end of the metal terminal located in the shell, and the other of the positive pole ear and the negative pole ear is connected to the inner wall of the shell; The pole piece of the wound battery cell is in the shape of a long strip. When one pole ear is provided on the pole piece, the pole ear is provided at the center of the length direction of the pole piece. When at least two pole ears are provided on the pole piece, at least two pole ears are provided at intervals along the length direction of the pole piece, and the pole ears extend to the outside of the wound battery cell. The metal terminal has at least a bonding area bonded to the adhesive layer; The bonding area is provided with a rough layer; or the bonding area is provided with a plurality of bonding protrusions protruding from the surface of the metal terminal; The shell is provided with a forming hole, the forming hole is spaced apart from the lead-out hole, and a waterproof and breathable membrane is arranged in the forming hole.

2. The wound lithium-ion battery according to claim 1, characterized in that: The base includes a seat plate, a first protrusion is protruding from one side of the seat plate, the mounting hole is opened on the seat plate and passes through the first protrusion, the first protrusion is plugged into and matched with the lead-out hole, and the seat plate abuts against the inner wall of the shell or the outer wall of the shell.

3. The wound lithium-ion battery according to claim 1, characterized in that: A reinforcing plate is fixed on the shell, the reinforcing plate is spaced apart from the lead-out hole, and the connection position between the pole ear and the shell is located at the reinforcing plate.

4. The wound lithium-ion battery according to claim 1, characterized in that: The shell comprises 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 in the thickness direction of the shell, and the cover body blocks the open end of the base shell.

5. The wound lithium-ion battery according to claim 4, characterized in that: The terminal assembly is mounted on a side of the base housing that is perpendicular to the cover body.

6. The wound lithium-ion battery according to claim 1, characterized in that: The shell is a cylindrical shell, an opening is provided on the arc-shaped side surface of the shell, and the opening is blocked by a cover.

7. The wound lithium-ion battery according to claim 1, characterized in that: A first insulating plate is arranged between the metal terminal and the inner wall of the housing.

8. The wound lithium-ion battery according to any one of claims 1 to 7, characterized in that: The pole piece of the wound battery cell comprises 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 the radial direction of the wound battery cell, the extension portion is partially overlapped after being bent, the extension portion is arranged at an angle with the pole piece, and the extension portion forms the pole ear; or, The pole piece of the wound battery cell comprises a current collector and an active material coated on the current collector, the current collector has an extension portion extending outside the active material along the axial direction of the wound battery cell, and the extension portion forms the pole lug.

9. The wound lithium-ion battery according to any one of claims 1 to 7, characterized in that: The wound battery cell comprises a positive electrode sheet, a negative electrode sheet and a separator arranged between the positive electrode sheet and the negative electrode sheet, wherein the separator has a separator extending along the axis direction of the wound battery cell to both ends of the negative electrode sheet, and the separator is used to isolate the electrode lug of the wound battery cell from the end surface of the wound battery cell; or, An insulating member is arranged between the pole tab and the end surface of the wound battery core.

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