A soft-pack button-type lithium-ion battery

Abstract

The present invention relates to a soft-package button-type lithium-ion battery, comprising a soft shell, a battery cell contained in the soft shell, and an insulating rod; the battery cell comprises a central through hole; it is in the form of a spiral winding, comprising multiple layers of positive electrodes and multiple layers of negative electrodes arranged alternately; at least two layers of positive electrodes in the multiple layers of positive electrodes are provided with positive electrode ears; at least two layers of negative electrodes in the multiple layers of negative electrodes are provided with negative electrode ears; the positive electrode ears and the negative electrode ears are respectively located at both ends of the battery cell; the positive electrode ears on at least two layers of positive electrodes and the negative electrode ears on at least two layers of negative electrodes both include a first state and a second state; in the first state, they are arranged side by side on one side of the central through hole and protrude from the end face of the battery cell and form a set angle with the end face of the battery cell; in the second state, they are all pressed downward toward the central through hole under the action of an external force to form a laminated structure to reduce internal resistance, and the output conductor is connected at the junction of the laminated structure and fixed by a thermal packaging form to lead out the electrode. The battery has low internal resistance, good fast charging performance, and high product yield.

Description

Technical Field

[0001] The invention relates to a lithium ion battery, and more particularly to a soft-package button-type lithium ion battery. Background Art

[0002] Soft-pack lithium-ion batteries have a wide range of applications. With the rise of wireless Bluetooth headsets, the growth rate of steel-shell button lithium-ion batteries has been very rapid, and there is a situation of supply exceeding demand. Traditional soft-pack lithium-ion batteries usually weld the pole ears to the empty foil area of ​​the pole piece, and stick insulating tape on them. Then they are cut into pieces required for the winding process, and the positive electrode, negative electrode and diaphragm are wound together on the winding equipment. Because the width of the button battery pole piece is very narrow, concentrated in 3-6mm, it is easy for the foil area to break, resulting in defects such as high internal resistance of the battery. At the same time, once the pole piece breaks, the entire battery will be scrapped, resulting in a high defect rate. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an improved soft-pack button-type lithium-ion battery.

[0004] The technical solution adopted by the present invention to solve the technical problem is: construct a soft-package button-type lithium-ion battery, including a soft shell, a battery cell accommodated in the soft shell, and an insulating rod inserted in the battery cell and having a length greater than the height of the battery cell;

[0005] The battery core comprises a central through hole for the insulating rod to pass through; the battery core is in the form of a spiral winding, comprising multiple layers of positive electrodes and multiple layers of negative electrodes arranged alternately; at least two layers of the positive electrodes in the multiple layers are provided with positive electrode ears; at least two layers of the negative electrodes in the multiple layers are provided with negative electrode ears; the positive electrode ears and the negative electrode ears are respectively located at two ends of the battery core;

[0006] The positive electrode tabs on at least two layers of positive electrodes and the negative electrode tabs on at least two layers of negative electrodes both include a first state and a second state;

[0007] In the first state, the positive electrode ears on at least two layers of positive electrodes are arranged side by side on one side of the central through hole and protrude from the end face of the battery cell and form a set angle with the end face of the battery cell; the negative electrode ears on at least two layers of negative electrodes are arranged side by side on one side of the central through hole and protrude from the end face of the battery cell and form a set angle with the end face of the battery cell;

[0008] In the second state, the positive pole ears on at least two layers of positive electrodes and the negative pole ears on at least two layers of negative electrodes are pressed downward toward the central through hole under the action of external force to form a stacked structure to reduce internal resistance, and the output conductor with pole ear glue that can pass through the soft shell and is arranged is connected at the joint of the stacked structure and fixed by thermal packaging, thereby leading out the electrode.

[0009] Preferably, the battery cell is columnar, and the lengths of the positive electrode lug and the negative electrode lug are both greater than the radius of the battery cell and smaller than the diameter of the battery cell.

[0010] Preferably, the battery cell comprises a first separator, a positive electrode sheet, a second separator and a negative electrode sheet stacked in sequence;

[0011] There are multiple positive electrode tabs, and the multiple positive electrode tabs are equidistantly arranged on the positive electrode sheet;

[0012] There are multiple negative electrode ears, and the multiple negative electrode ears are equidistantly arranged on the negative electrode sheet.

[0013] Preferably, the first separator, the positive electrode sheet, the second separator and the negative electrode sheet are formed into a composite sheet by thermal bonding;

[0014] The battery core is formed by winding the composite sheet.

[0015] Preferably, the positive electrode sheet is provided with a first empty foil area on a long side close to one side thereof;

[0016] A plurality of the positive electrode tabs are arranged side by side and at intervals in the first empty foil area;

[0017] The negative electrode sheet is provided with a second empty foil area on a long side close to one side thereof;

[0018] A plurality of the negative electrode tabs are arranged side by side and at intervals in the second empty foil area.

[0019] Preferably, the set angle is 0 to 90 degrees.

[0020] Preferably, the positive electrode tab and the negative electrode tab are in the shape of longitudinal sheets, and the width of the positive electrode tab and / or the negative electrode tab is 3-6 mm.

[0021] Preferably, each layer of the positive electrode is arranged corresponding to one of the positive electrode ears.

[0022] Preferably, each layer of the negative electrode is arranged corresponding to a negative electrode ear.

[0023] Preferably, the soft shell is an aluminum-plastic film.

[0024] The implementation of the soft-package button-type lithium-ion battery of the present invention has the following beneficial effects: the soft-package button-type lithium-ion battery is provided with positive pole ears on at least two layers of the multi-layer positive poles of the battery cell in the soft shell, and negative pole ears are provided on at least two layers of the negative poles in the multi-layer negative poles, and the positive pole ears and the negative pole ears are divided into two ends of the battery cell. When the soft-package button-type lithium-ion battery is assembled, the positive pole ears and the negative pole ears that protrude from the end face of the battery cell in the first state and form a set angle with the end face of the battery cell can be pressed downward in the direction of the central through hole of the positive pole ears and the negative pole ears that are provided by the external force to form a laminated structure that can reduce the internal resistance, and the output conductor with pole ear glue that can pass through the soft shell is connected at the junction of the laminated structure and fixed by heat packaging to lead out the electrode. By providing positive pole ears on at least two layers of positive electrodes and negative pole ears on at least two layers of negative electrodes, it is possible to avoid the battery being scrapped after a single pole ear is broken. By forming a laminated structure with at least two pole ears, the internal resistance of the battery can be greatly reduced, thereby improving the fast charging characteristics of the battery. The soft-pack button-type lithium-ion battery has the advantages of simple structure, small internal resistance, good fast charging performance and high product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0026] Figure 1 is a partial structural schematic diagram of a soft-package button-type lithium-ion battery in some embodiments of the present invention;

[0027] Figure 2 yes Figure 1 The schematic diagram of the structure of the battery cell of the soft-pack button-type lithium-ion battery is shown. DETAILED DESCRIPTION

[0028] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0029] Figure 1 and Figure 2 Some preferred embodiments of the soft-pack button-type lithium-ion battery of the present invention are shown. The soft-pack button-type lithium-ion battery can be widely used in various fields such as 3C digital, smart wear, electric vehicles, medical, and military. It can avoid the battery being scrapped after a single tab is broken, and it can greatly reduce the internal resistance of the battery, thereby improving the fast charging characteristics of the battery and thus improving the product yield. The soft-pack button-type lithium-ion battery has the advantages of simple structure, small internal resistance, good fast charging performance, and high product yield.

[0030] like Figure 1 and Figure 2As shown, further, in some embodiments, the soft-package button-type lithium-ion battery may include a soft shell 10, a battery cell 20, and an insulating rod 30. Further, in some embodiments, the soft shell 10 can be used to accommodate the battery cell 20 and the insulating rod 30. The battery cell 20 can be disposed in the soft shell 10, which can generate electrical energy through an electrochemical reaction. The insulating rod 20 can be inserted into the battery cell 20, which can be used to absorb and store the electrolyte injected into the winding core 10.

[0031] Further, in some embodiments, the soft shell 10 can be a film, specifically, in some embodiments, the soft shell 10 can be an aluminum-plastic film, and the good oxygen barrier, moisture resistance, puncture resistance, high strength, high toughness, unidirectional or bidirectional air permeability, UV resistance, and chemical resistance of the aluminum-plastic film can be used to protect the battery cell 20. It can be understood that in some other embodiments, the soft shell 10 may not be limited to the aluminum-plastic film. In some embodiments, the soft shell 10 can be cylindrical, which can be wrapped around the periphery of the battery cell 20.

[0032] Further, in some embodiments, the battery cell 20 may be columnar and may include a central through hole 21, and the central through hole 21 may be provided for the insulating rod to pass through. The battery cell 20 may be in the form of a spiral winding, which may include multiple layers of positive electrodes and multiple layers of negative electrodes arranged alternately, and a separation layer arranged between adjacent positive electrodes and negative electrodes. Further, specifically, the battery cell 20 may include a first diaphragm, a positive electrode sheet, a second diaphragm, and a negative electrode sheet stacked in sequence. It may be formed by winding a composite sheet formed by heat-compression bonding the first diaphragm, the positive electrode sheet, the second diaphragm, and the negative electrode sheet stacked in sequence. The positive electrode sheet may be wound to form multiple layers of positive electrodes, the negative electrode sheet may be wound to form multiple layers of negative electrodes, and the second diaphragm may be wound to form multiple layers of separation layers.

[0033] The positive electrode sheet may include a positive electrode substrate and a positive electrode material coated on the positive electrode substrate. The positive electrode substrate may be a current collector of an aluminum foil, and may be in the form of a long strip. In some embodiments, the positive electrode sheet is provided with a first empty foil area near one long side thereof. The positive electrode material may be uniformly coated on the positive electrode substrate and located outside the first empty foil area.

[0034] The negative electrode sheet may include a negative electrode substrate and a negative electrode material coated on the negative electrode substrate. The negative electrode substrate may be a current collector of a copper foil material, and it may also be in the form of a long strip. The long side of the negative electrode sheet close to one side thereof is provided with a second empty foil area, and the negative electrode material may be uniformly coated on the negative electrode substrate and located outside the second empty foil area.

[0035] The first separator may be arranged on one side of the positive electrode sheet, and located at the uppermost layer of the composite sheet. One side of the first separator is coated with a hot melt material. The hot melt material may be coated on the side of the first separator opposite to the positive electrode sheet. The hot melt material may be a hot melt adhesive, which may melt under heating to quickly bond the first separator and the positive electrode sheet.

[0036] The second separator can be arranged between the positive electrode sheet and the negative electrode sheet, and both sides of the second separator are coated with hot-melt material, which can melt under heating to quickly bond the second separator to the positive electrode sheet and the negative electrode sheet respectively.

[0037] In some embodiments, the battery cell 10 can improve the winding efficiency by using the composite sheet for winding, avoid the misalignment of the first diaphragm, the positive electrode sheet, the second diaphragm, and the negative electrode sheet, and reduce the contact of human hands to avoid the influence of dust and water vapor, so as to maximize the quality of the lithium battery. In addition, by forming the composite sheet through hot bonding, the die-cutting process can be omitted, thereby reducing the generation of burrs, thereby avoiding the risk of low-voltage fracture of the battery.

[0038] Further, in some embodiments, at least two layers of the multi-layer positive electrode are provided with positive electrode ears 22. Specifically, in some embodiments, the positive electrode ears 22 can be multiple, and the multiple positive electrode ears 22 can be arranged corresponding to the multi-layer positive electrode, and each layer of positive electrode can be arranged corresponding to a layer of positive electrode ears. Specifically, in some embodiments, the multiple positive electrode ears 22 can be arranged equidistantly on the positive electrode sheet, and the center distance between two adjacent positive electrode ears 22 can be adapted to the circumference of the battery cell, so that after the positive electrode sheet is wound, the multiple positive electrode ears 22 can all be located on the same side of the central through hole 21. In some embodiments, specifically, the multiple positive electrode ears 22 can be arranged side by side and spaced apart in the first empty foil area by ultrasonic welding or laser welding before the positive electrode sheet is hot-compressed.

[0039] Further, in some embodiments, the positive electrode ear 22 may be in the form of a longitudinal sheet, which may be an aluminum metal strip, and its width may be 3-6 mm. It is understandable that in some other embodiments, the width of the positive electrode ear 22 may not be limited to 3-6 mm. In some embodiments, the length of the positive electrode ear 22 is greater than the radius of the battery cell 20 and less than the diameter of the battery cell 20, and can extend radially along the battery cell 20, covering the central through hole 21, and can avoid protruding from the outer periphery of the battery cell 20, thereby preventing it from being loaded into the soft shell 10. In some embodiments, the plurality of positive electrode ears 22 may be arranged with equal length. Of course, it is understandable that in some other embodiments, its length decreases slightly toward the central through hole.

[0040] Further, in some embodiments, the positive electrode ear 22 may include a first state and a second state. The first state is a state before assembly. The second state is a state after assembly. When the positive electrode ear 22 is in the first state, the positive electrode ears 22 on the at least two layers of positive electrodes may be arranged side by side on one side of the central through hole 21 and protrude from the end face of the battery cell 20 and form a set angle with the end face of the battery cell 20. Specifically, the positive electrode ear 22 may be arranged perpendicular to the end face of the battery cell 20, and the set angle may be 90°. Of course, it can be understood that in some other embodiments, it may not be limited to a right angle, it may be an acute angle, and the angle of the set angle may be 0 to 90°. When the positive electrode ear 22 is in the second state, it can be pressed downward toward the center through hole 21 under the action of external force. The positive electrode ears 22 on the at least two layers of positive electrodes can be stacked to form a laminated structure, and can be abutted against the end of the insulating rod 30. The output conductor with the electrode ear glue is connected at the joint of the laminated structure, and the output conductor is passed through the soft shell 10 and fixed by heat packaging to lead out the electrode. Specifically, the output conductor with the electrode ear glue can be fixed to the joint of the laminated structure by welding. By arranging multiple positive electrode ears 22, it is possible to avoid the entire battery being scrapped after a single positive electrode ear breaks, and a parallel circuit structure can be formed, which is equivalent to several batteries in parallel, thereby reducing the internal resistance of the battery cell, improving the fast charging characteristics of the battery, and improving the product yield.

[0041] Further, in some embodiments, at least two layers of the multi-layer negative electrode are provided with negative electrode ears 23. The positive electrode ears 22 and the negative electrode ears 23 may be respectively located at the two ends of the battery cell 20. Specifically, in some embodiments, the negative electrode ears 23 may be multiple, and the multiple negative electrode ears 23 may be arranged corresponding to the multi-layer negative electrode, and each layer of negative electrode may be arranged corresponding to one layer of negative electrode ears. Specifically, in some embodiments, the multiple negative electrode ears 23 may be arranged equidistantly on the negative electrode sheet, and the center distance between two adjacent negative electrode ears 23 may be adapted to the circumference of the battery cell, so that after the negative electrode sheet is wound, the multiple negative electrode ears 23 may be located on the same side of the central through hole 21. In some embodiments, specifically, the multiple negative electrode ears 23 may be arranged side by side and spaced apart in the first empty foil area by ultrasonic welding or laser welding before the negative electrode sheet is hot-compressed.

[0042] Further, in some embodiments, the negative pole ear 23 may be in the shape of a longitudinal sheet, which may be a copper metal strip, and its width may be 3-6 mm. It is understandable that in some other embodiments, the width of the negative pole ear 23 may not be limited to 3-6 mm. In some embodiments, the length of the negative pole ear 23 is greater than the radius of the battery cell 20 and less than the diameter of the battery cell 20, and can extend radially along the battery cell 20, covering the central through hole 21, and can avoid protruding from the outer periphery of the battery cell 20, thereby preventing it from being loaded into the soft shell 10. In some embodiments, the multiple negative pole ears 22 may be arranged with equal length. Of course, it is understandable that in some other embodiments, its length decreases slightly toward the central through hole.

[0043] Further, in some embodiments, the negative electrode ear 23 may include a first state and a second state. The first state is a state before assembly. The second state is a state after assembly. When the negative electrode ear 23 is in the first state, the negative electrode ears 23 on the at least two layers of negative electrodes may be arranged side by side on one side of the central through hole 21 and protrude from the end face of the battery cell 20 and form a set angle with the end face of the battery cell 20. Specifically, the negative electrode ear 23 may be arranged perpendicular to the end face of the battery cell 20, and the set angle may be 90°. Of course, it can be understood that in some other embodiments, it may not be limited to a right angle, it may be an acute angle, and the angle of the set angle may be 0 to 90°. When the negative electrode ear 23 is in the second state, it can be pressed downward toward the central through hole 21 under the action of external force. The negative electrode ears 23 on the at least two layers of negative electrodes can be stacked to form a laminated structure, and can be abutted against the end of the insulating rod 30. The output conductor with the ear glue is connected at the junction of the laminated structure, and the output conductor is passed through the soft shell 10 and fixed by heat packaging to lead out the electrode. Specifically, the output conductor with the ear glue can be fixed to the junction of the laminated structure by welding. By setting a plurality of negative electrode ears 23, it can be avoided that a single negative electrode ear breaks and causes the entire battery to be scrapped. In addition, the positive electrode ear 22 and the negative electrode ear 23 are arranged side by side and are respectively located on two opposite sides of the central through hole 21. The positive electrode ears 22 and the negative electrode ears 23 on the adjacent positive and negative electrodes can form a group of electrodes, thereby forming a circuit structure of multiple groups in parallel, which is equivalent to several batteries in parallel, thereby reducing the internal resistance of the battery cell, improving the fast charging characteristics of the battery, and improving the product yield.

[0044] Further, in some embodiments, the insulating rod 30 can be inserted into the central through hole 21, and its length can be greater than the height of the battery cell 20, and its two ends can be inserted from the central through hole 21, so that the positive ear 22 and the negative ear 23 can be supported in the second state, so that the positive ear 22 is isolated from the positive electrode, and the negative ear 23 is isolated from the negative electrode, so that short circuit can be avoided, thereby improving the yield of the product. Further, in some embodiments, the shape and size of the insulating rod 30 can be comparable to the shape and size of the central through hole 11. The insulating rod 30 can be cylindrical, and its outer diameter can be slightly smaller than the inner diameter of the central through hole 11. Of course, it can be understood that in some other embodiments, the outer diameter of the insulating rod 20 can also be equal to the inner diameter of the central through hole 11, so that it can be closely fitted with the inner wall of the central through hole 11. In some embodiments, the insulating rod 30 can be made of insulating material as a whole, specifically, it can be made of PP or PET.

[0045] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. A soft-pack button-type lithium-ion battery, characterized in that: It comprises a soft shell (10), a battery core (20) accommodated in the soft shell (10), and an insulating rod (30) inserted into the battery core (20) and having a length greater than the height of the battery core (20); The battery core (20) comprises a central through hole (21) for the insulating rod to pass through; the battery core (20) is in the form of a spiral winding, comprising multiple layers of positive electrodes and multiple layers of negative electrodes arranged alternately; at least two layers of the positive electrodes in the multiple layers are provided with positive electrode ears (22); at least two layers of the negative electrodes in the multiple layers are provided with negative electrode ears (23); the positive electrode ears (22) and the negative electrode ears (23) are respectively located at two ends of the battery core (20); The positive electrode ears (22) on at least two layers of positive electrodes and the negative electrode ears (23) on at least two layers of negative electrodes both include a first state and a second state; In the first state, the positive electrode ears (22) on at least two layers of positive electrodes are arranged side by side on one side of the central through hole (21) and protrude from the end face of the battery cell (20) and form a set angle with the end face of the battery cell (20); the negative electrode ears (23) on at least two layers of negative electrodes are arranged side by side on one side of the central through hole (21) and protrude from the end face of the battery cell (20) and form a set angle with the end face of the battery cell (20); In the second state, the positive electrode ears (22) on at least two layers of positive electrodes and the negative electrode ears (23) on at least two layers of negative electrodes are pressed downward toward the central through hole (21) under the action of external force to form a stacked structure to reduce internal resistance, and an output conductor with ear glue that can pass through the soft shell (10) is connected at the joint of the stacked structure and fixed in a thermal packaging form, thereby leading out the electrode.

2. The soft-pack button-type lithium-ion battery according to claim 1, characterized in that: The battery core (20) is columnar, and the lengths of the positive electrode tab (22) and the negative electrode tab (23) are both greater than the radius of the battery core (20) and smaller than the diameter of the battery core (20).

3. The soft-pack button-type lithium-ion battery according to claim 1, characterized in that: The battery cell (20) comprises a first diaphragm, a positive electrode sheet, a second diaphragm and a negative electrode sheet which are stacked in sequence; There are a plurality of positive electrode tabs (22), and the plurality of positive electrode tabs (22) are arranged on the positive electrode sheet at equal intervals; There are a plurality of negative electrode ears (23), and the plurality of negative electrode ears (23) are arranged on the negative electrode sheet at equal intervals.

4. The soft-pack button-type lithium-ion battery according to claim 3, characterized in that: The first separator, the positive electrode sheet, the second separator and the negative electrode sheet are formed into a composite sheet by thermal bonding; The battery core (20) is formed by winding the composite sheet.

5. The soft-pack button-type lithium-ion battery according to claim 3, characterized in that: The positive electrode sheet is provided with a first empty foil area on a long side close to one side thereof; A plurality of positive electrode tabs (22) are arranged side by side and at intervals in the first empty foil area; The negative electrode sheet is provided with a second empty foil area on a long side close to one side thereof; A plurality of negative electrode tabs (23) are arranged side by side and at intervals in the second empty foil area.

6. The soft-pack button-type lithium-ion battery according to claim 1, characterized in that: The set angle is 0-90°.

7. The soft-pack button-type lithium-ion battery according to claim 1, characterized in that: The positive electrode tab (22) and the negative electrode tab (23) are in the shape of longitudinal sheets, and the width of the positive electrode tab (22) and / or the negative electrode tab (23) is 3-6 mm.

8. The soft-pack button-type lithium-ion battery according to claim 1, characterized in that: Each layer of the positive electrode is arranged correspondingly to a positive electrode ear.

9. The soft-pack button-type lithium-ion battery according to claim 1, characterized in that: Each layer of the negative electrode is arranged correspondingly to a negative electrode ear.

10. The soft-pack button-type lithium-ion battery according to claim 1, characterized in that: The soft shell (10) is an aluminum-plastic film.

Images