CN111341991A - Method for preventing electrode lug from being inserted reversely and reducing battery cell failure - Google Patents
Method for preventing electrode lug from being inserted reversely and reducing battery cell failure Download PDFInfo
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- CN111341991A CN111341991A CN202010151977.9A CN202010151977A CN111341991A CN 111341991 A CN111341991 A CN 111341991A CN 202010151977 A CN202010151977 A CN 202010151977A CN 111341991 A CN111341991 A CN 111341991A
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- 238000000034 method Methods 0.000 title claims abstract description 53
- 238000003466 welding Methods 0.000 claims description 117
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 4
- 239000012528 membrane Substances 0.000 claims description 3
- 230000001681 protective effect Effects 0.000 claims description 3
- 229910052786 argon Inorganic materials 0.000 claims description 2
- 239000007789 gas Substances 0.000 claims description 2
- 229910052757 nitrogen Inorganic materials 0.000 claims description 2
- 238000003780 insertion Methods 0.000 abstract description 15
- 230000037431 insertion Effects 0.000 abstract description 15
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- 238000004880 explosion Methods 0.000 abstract description 3
- 230000000694 effects Effects 0.000 description 10
- 238000004804 winding Methods 0.000 description 10
- 238000002955 isolation Methods 0.000 description 7
- 239000011521 glass Substances 0.000 description 6
- 238000012216 screening Methods 0.000 description 6
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- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- 230000004888 barrier function Effects 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
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- 238000002360 preparation method Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 208000032953 Device battery issue Diseases 0.000 description 1
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
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- 229910001416 lithium ion Inorganic materials 0.000 description 1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/50—Current conducting connections for cells or batteries
- H01M50/531—Electrode connections inside a battery casing
- H01M50/54—Connection of several leads or tabs of plate-like electrode stacks, e.g. electrode pole straps or bridges
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/50—Current conducting connections for cells or batteries
- H01M50/572—Means for preventing undesired use or discharge
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Connection Of Batteries Or Terminals (AREA)
Abstract
The invention relates to a method for preventing electrode lugs from being inserted reversely to reduce battery core failure, which comprises the following steps: prewelding the roots of the multilayer tabs, integrating the multilayer tabs, and obtaining the naked battery core. According to the method provided by the invention, the root parts of the multilayer tabs are prewelded, so that the root parts of the tabs realize interatomic fusion and permeation, the root parts of the tabs are firmly fused into a whole, the integration of the multilayer tabs is realized, the problem of inverted insertion of the multilayer tabs is solved, and the anode plate and the cathode plate are prevented from contacting due to the bending caused by the redundant tab length in the assembling and forming process of a naked battery cell, so that short circuit, fire and explosion occur, and the purpose of reducing the failure of the battery cell is achieved; the method is simple to operate and has high application value.
Description
Technical Field
The invention relates to the technical field of batteries, in particular to a method for preventing lugs from being inserted reversely to reduce the failure of a battery core.
Background
With the rapid development of commercial batteries, the market demand for energy density of batteries is higher and higher. In order to further increase the energy density of the battery, the main technical routes are as follows: (1) adopting high compaction density and increasing the thickness of the pole piece; (2) reducing the space occupied by inactive materials in the battery, and the like.
At present, in order to improve the space utilization rate of a cell shell, a tab in a cell is concerned widely. There are two main studies: on one hand, more space in the thickness direction of the tab is utilized, so that the tab is continuously extruded, and the root of the tab is extruded possibly to cause extrusion deformation and reverse insertion in the extrusion process; on the other hand, for the battery core with the multilayer tabs wound or laminated, the multilayer tabs need to be folded in half, but because the lengths of the tabs after being folded in half are inconsistent, the top edges of the tabs after being folded in half may be dislocated, and the situation of reverse insertion occurs. In order to solve the above problems, researchers have conducted intensive research.
CN206574785U discloses an electric core, which includes electric core body and the multilayer tab electrically connected with electric core body, wherein, one side of electric core body is the longest tab, the other side is the shortest tab, the length of multilayer tab is gradually increased from the shortest tab to the longest tab, the length difference of adjacent tab in multilayer tab satisfies the calculation formula: and Ld/(n-1), wherein Ld is the length difference of adjacent tabs, H is the thickness of the multilayer tab, and n is the number of tabs. The utility model discloses an electric core directly makes the utmost point ear of different length when utmost point ear shaping for coiling or laminated electric core realize utmost point ear topside automatic alignment after utmost point ear fifty percent discount, solved the problem of utmost point ear topside dislocation behind the utmost point ear fifty percent discount, but can not solve the problem that utmost point ear takes place to fall to insert behind the fifty percent discount.
CN110323403A discloses a safe tab structure, a preparation method thereof and a lithium ion battery, wherein the tab structure comprises a multilayer tab, and a shaping piece is wrapped at the root of the multilayer tab in a hot-pressing manner. The preparation method comprises the following steps: s1, sequentially laminating the multilayer negative plate, the diaphragm and the multilayer positive plate; wherein, both sides of each layer of negative plate are respectively connected with a negative tab, and both sides of each layer of positive plate are respectively connected with a positive tab; the positive electrode lugs and the negative electrode lugs are arranged in a staggered manner; s2, winding the stacked multilayer negative electrode sheets, the diaphragm and the multilayer positive electrode sheets together to form a bare cell with a multilayer positive electrode tab and a multilayer negative electrode tab; and S3, pressing and shaping the thermoplastic material at the root of the multilayer positive lug by using a hot pressing mechanism to form a shaping piece wrapping the root of the positive lug. The packaging of the fixed part increases the process steps, the production cost and the occupied space of inactive substances, and in addition, the fixed part has limited service life and can lose the bonding effect for a long time to fall off.
CN208862096U discloses assembly structure of power battery top cap and electric core, including top cap and electric core, the top cap is provided with first utmost point post and second utmost point post, the electric core is provided with first utmost point ear and second utmost point ear, first utmost point ear through first connection piece with first utmost point post electric connection, the second utmost point ear through the second connection piece with second utmost point post electric connection still includes first utmost point ear screening glass and the second utmost point ear screening glass that is used for preventing utmost point ear from inserting backward, first utmost point ear screening glass with the second utmost point ear screening glass all set up in the electric core top with between the top cap. Compared with the prior art, the utility model discloses a set up first utmost point ear screening glass and second utmost point ear screening glass between electric core top and top cap, not only play the effect of insulating top cap and electric core, can prevent utmost point ear from inserting upside down and with the connection piece short circuit simultaneously to effectively avoid the battery short circuit risk, improve the security performance of battery greatly. However, the provision of the protective sheet increases the production cost and the occupied space of the inactive material, which is not favorable for increasing the energy density of the battery.
Based on the research of the prior art, how to reduce the space occupied by the inactive substance, the simple effective prevention utmost point ear dislocation when, solves the problem of the back-off of multilayer utmost point ear, becomes the technical problem that awaits solution at present.
Disclosure of Invention
In order to solve the technical problem, the invention provides a method for preventing the pole lug from being inserted backwards. The method integrates the multilayer tabs by pre-welding the roots of the multilayer tabs, does not increase the fixed parts for integrating the tabs, reduces the occupied space of non-active substances, effectively prevents the tabs from being misplaced and solves the problem of reverse insertion of the multilayer tabs. By the method, the risk of battery failure is reduced.
In the invention, the expression of preventing the lugs from being inserted reversely to reduce the failure of the battery cell means that the multilayer lugs are integrated by pre-welding the roots of the multilayer lugs, so that the lugs can be prevented from being misplaced, the problem of inserting the multilayer lugs reversely can be solved, and the purpose of reducing the failure of the battery cell can be achieved.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a method for preventing a tab from being inserted upside down, the method comprising the steps of:
prewelding the roots of the multilayer tabs, integrating the multilayer tabs, and obtaining the naked battery core.
According to the method provided by the invention, the root parts of the multilayer tabs are pre-welded to realize interatomic fusion and permeation, and the root parts of the tabs are firmly fused into a whole, so that the integration of the multilayer tabs is realized, the dislocation of the tabs is effectively prevented, the problem of inverted insertion of the multilayer tabs is solved, and the problem that a positive plate and a negative plate are contacted and short-circuited, ignited and exploded due to the bending caused by the redundant length of the tabs in the assembling and forming process of a bare cell is avoided, so that the purpose of reducing the failure of the cell is achieved; the method is simple to operate, compared with the prior art, the method has the advantages that a fixed piece is not added, the occupied space of the multilayer tab is reduced, and the method has higher application value.
In the invention, the root part is a position close to the joint of the tab and the pole piece and not exceeding the height 1/3 of the tab.
In the invention, the integration means that the roots of the multilayer tabs are fused by prewelding so that the tabs are arranged in order.
Preferably, the multilayer tab is a multilayer positive tab and/or a multilayer negative tab.
Preferably, the number of layers of the tab in the multilayer tab is not less than 2, and may be, for example, 2, 3, 5, 8 or 10 layers, and the number of layers of the tab is determined by the requirements of the battery such as capacity and rate.
In the present invention, the shape of the multilayer tab is not particularly limited, and any shape commonly used by those skilled in the art may be used in the present invention.
Preferably, the shape of the multi-layer tab comprises a rectangle or a trapezoid.
In the invention, the trapezoid is a trapezoid placed in the forward direction and a trapezoid not placed in the reverse direction, because the trapezoid is inverted, the narrower side is connected with the pole piece, and in the process of assembling and forming the battery cell, the wider side can contact with the positive pole piece and/or the negative pole piece to cause short circuit and influence the yield of the battery cell.
Preferably, the shape of the multilayer tab is trapezoidal, and the width of the upper bottom is 10-20mm, which may be 10mm, 12mm, 15mm, 18mm or 20mm, etc.; the width of the lower base is 30-40mm, for example 30mm, 32mm, 35mm, 38mm or 40 mm.
In the invention, the lower bottom of the trapezoidal tab is connected with the pole piece, and the position close to the connection position and not exceeding the height 1/3 of the trapezoidal tab is the root of the trapezoidal tab.
Preferably, the height of the multi-layer tab is 25-45mm, and may be 25mm, 28mm, 30mm, 33mm, 35mm, 38mm, 40mm, 42mm or 45mm, for example.
In the invention, the bare cell before prewelding is not specifically limited, and any type commonly used by those skilled in the art, including multi-layer tabs, is suitable for the invention.
Preferably, the pre-welding mode comprises any one or a combination of at least two of ultrasonic welding, laser welding or resistance welding, and the ultrasonic welding is preferred.
The ultrasonic welding belongs to ultrasonic physical welding, so that the root parts of the lugs are subjected to interatomic fusion and penetration, compared with the method for fixing the root parts of the lugs by gluing in the prior art, the ultrasonic welding is firmer, raw materials can be saved, and the space occupied by inactive substances can be reduced.
Preferably, the time of the ultrasonic welding is 0.5 to 3s, and may be, for example, 0.5s, 0.8s, 1s, 1.3s, 1.5s, 1.7s, 2s, 2.2s, 2.5s, 2.8s, 3s, or the like, preferably 1 to 2.5 s.
Preferably, the pressure of the ultrasonic welding is 15 to 50Psi, for example, 15Psi, 18Psi, 20Psi, 25Psi, 30Psi, 35Psi, 40Psi, 45Psi, or 50Psi, etc., preferably 20 to 40Psi MPa.
Preferably, the power of the ultrasonic welding is 1500-.
Preferably, the ultrasonic welding has a frequency of 10 to 60kHz, and may be, for example, 10kHz, 15kHz, 20kHz, 25kHz, 30kHz, 35kHz, 40kHz, 45kHz, 50kHz, 55kHz, 60kHz, or the like, preferably 15 to 45 kHz.
Preferably, the power of the laser welding is 3000-.
Preferably, the focal length of the laser welding is-10-0 mm, for example, -10mm, -9.5mm, -9mm, -8mm, -7mm, -6mm, -5mm, -3mm, -2mm, -1mm, -0.5mm, 0mm, etc., preferably-2 to-8 mm. In laser welding, the focal length of the focal point just falling on the surface of an object is taken as a zero point, the focal point above the surface of the object is positive, and the focal point below the surface of the object is negative.
Preferably, the laser welding time is 0.5-3s, for example, 0.5, 0.88, 1.0, 1.5, 2.0, 2.5, 3.0, preferably 1-2.5 s.
Preferably, the protective gas for the laser welding comprises nitrogen and/or argon.
Preferably, the current for resistance welding is 20-80A, for example 20A, 25A, 30A, 35A, 40A, 45A, 50A, 60A, 70A, 75A or 80A, etc., preferably 20-50A.
Preferably, the time of the resistance welding is 2-15s, for example, 2s, 3s, 5s, 8s, 10s, 13s, 15s, etc., preferably 2-10 s.
Preferably, the pressure for the resistance welding is 100-600kgf, for example, 100kgf, 150kgf, 200kgf, 250kgf, 300kgf, 350kgf, 400kgf, 450kgf, 500kgf, 550kgf or 600kgf, preferably 200-500 kgf.
In the invention, technological parameters of ultrasonic welding, laser welding and resistance welding are mutually matched to realize interatomic fusion and penetration at the root of the tab, the technological parameters are determined by the material and the layer number of the tab, and the tab is possibly penetrated due to overlarge selection of the technological parameters and the generated metal welding scrap is increased; the process parameter selection is too small, the welding effect is poor, and the lugs fall off.
Preferably, the bare cell comprises a positive plate, a separation film and a negative plate, and the separation film is positioned between the positive plate and the negative plate.
Preferably, the perpendicular distance between the position of the pre-welding and the upper edge of the isolating membrane is 3-15mm, for example, 3mm, 5mm, 8mm, 10mm, 12mm or 15mm, and if the distance is less than 3mm, the isolating membrane may be damaged by the welding process; the distance is more than 15mm, the root of the tab is loose, and the effect of preventing reverse insertion cannot be achieved; preferably 5-10 mm.
Preferably, the pre-welded welding head is a square welding head or a round spot welding head.
Preferably, the length of the square welding head does not exceed the minimum width of the multi-layer tab.
Preferably, the width of the square welding head is less than or equal to 10mm, for example, 10mm, 8mm, 5mm, 3mm, 1mm or 0.5mm, and the like, and preferably 5-8 mm.
Preferably, the diameter of the round spot-shaped welding head is less than or equal to 10mm, such as 10mm, 8mm, 5mm, 3mm, 1mm or 0.5mm, and preferably 5-8 mm.
In the invention, the size of the welding head used for welding is determined according to the layer number of the pole lug and the area of the pole lug.
As a further preferred embodiment of the present invention, the method comprises the steps of:
prewelding the roots of the multilayer tabs, and integrating the multilayer tabs to obtain a naked battery core;
the multilayer tab has at least 2 layers, is trapezoidal, and has an upper bottom with a width of 10-20mm, a lower bottom with a width of 30-40mm and a height of 25-45 mm;
the root part is as follows: the vertical distance between the multilayer tab and the upper edge of the isolating film is 3-15 mm;
the prewelding mode is as follows: the circular point-shaped welding head with the diameter less than or equal to 10mm is adopted to carry out ultrasonic welding for 0.5-3s under the conditions that the pressure is 15-50Psi, the power is 1500-6000W and the frequency is 10-60 kHz.
In a second aspect, the present invention provides a bare cell comprising a bare cell prepared according to the method of the first aspect.
The roots of the multilayer tabs of the bare cell provided by the invention are fused together without scattering, so that the space occupied by the tabs is saved, and the safety problems of fire, explosion and the like caused by short circuit caused by the contact of the multilayer tabs with the positive plate and/or the negative plate due to reverse insertion can be effectively prevented.
In a third aspect, the present invention further provides a battery, which includes the bare cell according to the second aspect.
The battery provided by the invention adopts the naked battery cell fused at the root of the multilayer tabs, so that the occupied space of the inactive substances and the failure risk are reduced, and the safety is high.
Compared with the prior art, the invention has the following beneficial effects:
(1) according to the method provided by the invention, prewelding is carried out on the root of the multilayer tab, so that the root of the tab realizes interatomic fusion and permeation, the root of the tab is firmly fused into a whole, the integration of the multilayer tab is realized, the dislocation of the tab can be prevented, the problem of reverse insertion of the multilayer tab can be solved, the safety problems of short circuit, fire, explosion and the like caused by the contact between a positive plate and a negative plate due to the reverse insertion of the multilayer tab are prevented, and the purpose of reducing the failure of a battery cell is achieved;
(2) compared with the prior art, the method provided by the invention has the advantages that a fixed piece is not added, the occupied space of the multilayer tab is reduced, raw materials are saved, the tabs can be firmly and effectively integrated, and the method has higher application value.
Drawings
Fig. 1 is a schematic structural diagram of a bare cell provided by the present invention.
Fig. 2 is a schematic structural diagram of a bare cell provided in the present invention.
Wherein, 1-isolation film, 2-multilayer tab and 3-welding print.
Detailed Description
The following further describes the technical means of the present invention to achieve the predetermined technical effects by means of embodiments with reference to the accompanying drawings, and the embodiments of the present invention are described in detail as follows.
Exemplarily, the present invention provides a bare cell, and the structural schematic diagram thereof is shown in fig. 1 and fig. 2. As can be seen from fig. 1 and 2, the bare cell includes a separation film 1 and a multilayer tab 2, a welding print 3 is provided at the root of the multilayer tab 2, and the welding print 3 is in the shape of a circular dot (see fig. 1) or a square (see fig. 2).
Example 1
The embodiment provides a method for preventing a tab from being inserted backwards, which comprises the following steps:
(1) sequentially stacking a positive plate, an isolating film and a negative plate for winding, wherein the width of the positive plate is smaller than that of the negative plate, the width of the negative plate is smaller than that of the isolating film, 2 trapezoidal lugs are respectively welded on the positive plate and the negative plate, and the upper bottom width, the lower bottom width and the height of each trapezoidal lug are respectively 10mm, 30mm and 25 mm;
(2) the root of trapezoidal utmost point ear, with the position that the last edge vertical distance of barrier film is 3mm, carry out laser welding, integrate utmost point ear obtains naked electric core.
Example 2
The embodiment provides a method for preventing a tab from being inserted backwards, which comprises the following steps:
(1) sequentially stacking a positive plate, an isolating film and a negative plate for winding, wherein the width of the positive plate is smaller than that of the negative plate, the width of the negative plate is smaller than that of the isolating film, 4 trapezoidal lugs are respectively welded on the positive plate and the negative plate, and the upper bottom width, the lower bottom width and the height of each trapezoidal lug are respectively 15mm, 35mm and 35 mm;
(2) the root of trapezoidal utmost point ear, and barrier film top edge vertical distance are 9 mm's position, carry out laser welding, integrate utmost point ear obtains naked electric core.
Example 3
The embodiment provides a method for preventing a tab from being inserted backwards, which comprises the following steps:
(1) sequentially stacking a positive plate, an isolating film and a negative plate for winding, wherein the width of the positive plate is smaller than that of the negative plate, the width of the negative plate is smaller than that of the isolating film, 6 trapezoidal lugs are respectively welded on the positive plate and the negative plate, and the upper bottom width, the lower bottom width and the height of each trapezoidal lug are respectively 20mm, 40mm and 45 mm;
(2) the root of trapezoidal utmost point ear, with the position that the last edge vertical distance of barrier film is 15mm, carry out laser welding, integrate utmost point ear obtains naked electric core.
Example 4
The embodiment provides a method for preventing a tab from being inserted backwards, which comprises the following steps:
(1) sequentially stacking a positive plate, an isolating film and a negative plate for winding, wherein the width of the positive plate is smaller than that of the negative plate, the width of the negative plate is smaller than that of the isolating film, 2 trapezoidal lugs are respectively welded on the positive plate and the negative plate, and the upper bottom width, the lower bottom width and the height of each trapezoidal lug are respectively 10mm, 30mm and 25 mm;
(2) and (3) at the root of the trapezoidal tab, in a position with a vertical distance of 3mm from the upper edge of the isolation film, using a circular copper welding head with a diameter of 3mm and a length of 5cm, carrying out resistance welding for 2s under the conditions that the current is 20A and the pressure is 600kgf, and integrating the tab to obtain a bare cell.
Example 5
The embodiment provides a method for preventing a tab from being inserted backwards, which comprises the following steps:
(1) sequentially stacking a positive plate, an isolating film and a negative plate for winding, wherein the width of the positive plate is smaller than that of the negative plate, the width of the negative plate is smaller than that of the isolating film, 3 trapezoidal lugs are respectively welded on the positive plate and the negative plate, and the upper bottom width, the lower bottom width and the height of each trapezoidal lug are respectively 15mm, 35mm and 35 mm;
(2) and (3) at the root of the trapezoidal tab, in a position with a vertical distance of 5mm from the upper edge of the isolation film, using a circular copper welding head with a diameter of 5mm and a length of 8cm, carrying out resistance welding for 6s under the conditions that the current is 35A and the pressure is 350kgf, and integrating the tab to obtain a bare cell.
Example 6
The embodiment provides a method for preventing a tab from being inserted backwards, which comprises the following steps:
(1) sequentially stacking a positive plate, an isolating film and a negative plate for winding, wherein the width of the positive plate is smaller than that of the negative plate, the width of the negative plate is smaller than that of the isolating film, 5 trapezoidal lugs are respectively welded on the positive plate and the negative plate, and the upper bottom width, the lower bottom width and the height of each trapezoidal lug are respectively 20mm, 40mm and 55 mm;
(2) and at the root of the trapezoidal tab, using a circular copper welding head with the diameter of 2mm and the length of 1cm at the position with the vertical distance of 12mm from the upper edge of the isolation film, carrying out resistance welding for 15s under the conditions that the current is 80A and the pressure is 100kgf, and integrating the tab to obtain a bare cell.
Example 7
The embodiment provides a method for preventing a tab from being inserted backwards, which comprises the following steps:
(1) sequentially stacking a positive plate, an isolating film and a negative plate for winding, wherein the width of the positive plate is smaller than that of the negative plate, the width of the negative plate is smaller than that of the isolating film, 3 trapezoidal lugs are respectively welded on the positive plate and the negative plate, and the upper bottom width, the lower bottom width and the height of each trapezoidal lug are respectively 10mm, 30mm and 25 mm;
(2) the root of the trapezoidal tab is vertically away from the upper edge of the isolation film by 3mm, a circular point-shaped welding head with the diameter of 5mm is adopted, ultrasonic welding is carried out for 3s under the conditions that the pressure is 15Psi, the power is 6000W and the frequency is 10kHz, and multiple layers of tabs are integrated to obtain a naked electric core.
Example 8
The embodiment provides a method for preventing a tab from being inserted backwards, which comprises the following steps:
(1) sequentially stacking a positive plate, an isolating film and a negative plate for winding, wherein the width of the positive plate is smaller than that of the negative plate, the width of the negative plate is smaller than that of the isolating film, 5 trapezoidal lugs are respectively welded on the positive plate and the negative plate, and the upper bottom width, the lower bottom width and the height of each trapezoidal lug are respectively 15mm, 35mm and 35 mm;
(2) and (3) at the root of the trapezoidal tab, in a position with a vertical distance of 7mm from the upper edge of the isolation film, adopting a circular point-shaped welding head with a diameter of 3mm, carrying out ultrasonic welding for 1.5s under the conditions that the pressure is 30Psi, the power is 4500W and the frequency is 35kHz, and integrating multiple layers of tabs to obtain a naked electric core.
Example 9
The embodiment provides a method for preventing a tab from being inserted backwards, which comprises the following steps:
(1) sequentially stacking a positive plate, an isolating film and a negative plate for winding, wherein the width of the positive plate is smaller than that of the negative plate, the width of the negative plate is smaller than that of the isolating film, 8 trapezoidal lugs are respectively welded on the positive plate and the negative plate, and the upper bottom width, the lower bottom width and the height of each trapezoidal lug are respectively 20mm, 40mm and 45 mm;
(2) and at the root of the trapezoidal tab, a square welding head with the length of 10mm and the width of 5mm is adopted at the position with the vertical distance of 15mm from the upper edge of the isolation film, ultrasonic welding is carried out for 0.5s under the conditions that the pressure is 50Psi, the power is 1500W and the frequency is 60kHz, and a plurality of layers of tabs are integrated to obtain a naked electric core.
Example 10
The only difference compared with example 7 is that the pressure of ultrasonic welding in step (2) was replaced with 20 Psi.
Example 11
The only difference compared with example 7 is that the pressure of ultrasonic welding in step (2) was replaced with 40 Psi.
Example 12
The difference from example 7 is only that the power of ultrasonic welding in step (2) was replaced with 1800W.
Example 13
The difference from example 7 is only that the power of ultrasonic welding in step (2) was replaced with 5500W.
Example 14
The only difference compared with example 7 was that the frequency of ultrasonic welding in step (2) was replaced with 15 kHz.
Example 15
The only difference compared with example 7 was that the frequency of ultrasonic welding in step (2) was replaced with 45 kHz.
Example 16
The only difference compared with example 7 is that the pressure of ultrasonic welding in step (2) was replaced with 10 Psi.
Example 17
The only difference compared with example 7 is that the power of ultrasonic welding in step (2) was replaced with 1000W.
Example 18
The only difference compared with example 7 is that the frequency of ultrasonic welding in step (2) was replaced with 5 kHz.
Comparative example 1
The only difference compared to example 7 is that the multi-layer tab root was not pre-welded.
Evaluation of bare cell failure
Firstly, observing whether welding scraps and welding slag are generated in the welding process, wherein the welding scraps and the welding slag are not generated, the welding scraps and the welding slag which are not visible to the naked eye are preferred, the welding scraps and the welding slag which are not visible to the naked eye are selected as a second choice, the welding scraps and the welding slag which are visible to the naked eye are unqualified, the unqualified items are directly eliminated, and the following tests are not needed;
and then, evaluating the welding effect of welding, judging whether the welded tab is scattered or not, wherein the scattered tab is unqualified, and then performing tension test on the welded tab which is not scattered, wherein the larger the tension is, the better the residual area of the welding part is recorded by the battery core after the tension test, and the larger the residual area is, the better the welding effect is.
And finally, making the naked electric core with good welding effect into an electric core, taking 10 same electric cores to respectively observe the root parts of the lugs under the CT, and comparing the electric cores with a comparative example.
The results of the welding effect evaluation are shown in table 1.
TABLE 1
The following points can be seen from table 1:
(1) the bare cell prepared in the embodiments 1 to 18 is inspected under CT, and the number of the reverse insertion of the tab is very small or even zero, so that the root of the multilayer tab is prewelded, the multilayer tab is integrated, the reverse insertion of the tab is effectively prevented, and the failure of the cell is reduced;
(2) combining example 7 with examples 10 and 11, it can be seen that the welding tension and residue increase with the increase of welding pressure, because the welding pressure is large, the gap between the tab and the tab is small, and the ultrasonic welding utilizes the infiltration fusion between atoms;
(3) combining example 7 with examples 12 and 13, it can be seen that the greater the pull and residue of the weld as the power is increased, because the greater the power is at the same time, the greater the energy generated by the operation of the welding head, and the more intense the penetration of atoms;
(4) combining example 7 with examples 14 and 15, it can be seen that the greater the vibration frequency of the horn, the greater the welding tension and residue, because of the higher vibration frequency, the more vigorous the atomic motion and the greater the penetration ability;
(5) it can be seen from the combination of the embodiment 7 and the embodiments 16-18 that the low welding pressure, the low welding power and the low welding frequency have no effective welding effect on the root of the tab and do not have beneficial effect on the inverted insertion of the tab, because the process parameters set by the embodiments 16-18 are not in the scope of the claims of the application, and the energy required for the penetration between atoms during welding can not be met;
(6) it can be seen from the combination of example 7 and comparative example 1 that the cells welded to the root of the tab did not exhibit the reverse insertion phenomenon when examined under CT, while the cells not welded to the root of the tab exhibited the reverse insertion phenomenon and were much more numerous when examined under CT, because the root of the multi-layer tab was not tack-welded in comparative example 1.
In conclusion, according to the method provided by the invention, the roots of the multilayer tabs are prewelded, so that the roots of the tabs are fused and penetrated among atoms, and the roots of the tabs are firmly fused into a whole, so that the integration of the multilayer tabs is realized, the dislocation of the tabs is effectively prevented, the problem of inverted insertion of the multilayer tabs is solved, and the problem that a positive plate and a negative plate are contacted and short-circuited, ignited and exploded due to the bending caused by the redundant length of the tabs in the assembling and forming process of a bare cell is avoided, so that the purpose of reducing the failure of the cell is achieved; the method is simple to operate, integrates the loose multi-layer tabs without adding other shaping pieces, reduces the occupied space of inactive substances, and has higher application value
The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must be implemented depending on the above detailed structural features. It should be understood by those skilled in the art that any modifications of the present invention, equivalent substitutions of selected components of the present invention, additions of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.
Claims (10)
1. A method for preventing a tab from being inserted upside down, the method comprising the steps of:
prewelding the roots of the multilayer tabs, integrating the multilayer tabs, and obtaining the naked battery core.
2. The method according to claim 1, wherein the multilayer tab is a multilayer positive tab and/or a multilayer negative tab;
preferably, the number of layers of the tab in the multilayer tab is more than or equal to 2.
3. The method of claim 1 or 2, wherein the shape of the multi-layer tab comprises a rectangle or a trapezoid;
preferably, the multilayer tab is trapezoidal, the width of the upper bottom is 10-20mm, and the width of the lower bottom is 30-40 mm;
preferably, the height of the multi-layer tab is 25-45 mm.
4. A method according to any one of claims 1-3, wherein the pre-welding comprises any one or a combination of at least two of ultrasonic welding, laser welding or resistance welding, preferably ultrasonic welding;
preferably, the time of the ultrasonic welding is 0.5 to 3s, preferably 1 to 2.5 s;
preferably, the pressure of the ultrasonic welding is 15 to 50Psi, preferably 20 to 40 Psi;
preferably, the power of the ultrasonic welding is 1500-;
preferably, the frequency of the ultrasonic welding is 10-60kHz, preferably 15-45 kHz.
5. The method as claimed in claim 4, wherein the laser welding power is 3000-6000W;
preferably, the focal length of the laser welding is-10-0 mm, preferably-2-8 mm;
preferably, the laser welding time is 0.5 to 3s, preferably 1 to 2.5 s;
preferably, the protective gas for the laser welding comprises nitrogen and/or argon.
6. A method according to any of the claims 4, characterized in that the current of the resistance welding is 20-80A, preferably 20-50A;
preferably, the resistance welding time is 2-15s, preferably 2-10 s;
preferably, the pressure for the resistance welding is 100-.
7. The method of any one of claims 1-6, wherein the bare cell comprises a positive plate, a separator and a negative plate, the separator being positioned between the positive plate and the negative plate;
preferably, the vertical distance between the position of the prewelding and the upper edge of the isolating membrane is 3-15mm, and preferably 5-10 mm;
preferably, the welding head for prewelding is a square welding head or a round point welding head;
preferably, the length of the square welding head does not exceed the minimum width of the multi-layer tab;
preferably, the width of the square welding head is less than or equal to 10mm, and preferably 5-8 mm;
preferably, the diameter of the round point-shaped welding head is less than or equal to 10mm, and preferably 5-8 mm.
8. The method according to any one of claims 1-7, characterized in that the method comprises the steps of:
prewelding the roots of the multilayer tabs, and integrating the multilayer tabs to obtain a naked battery core;
the multilayer tab has at least 2 layers, is trapezoidal, and has an upper bottom with a width of 10-20mm, a lower bottom with a width of 30-40mm and a height of 25-45 mm;
the root part is as follows: the vertical distance between the multilayer tab and the upper edge of the isolating film is 3-15 mm;
the prewelding mode is as follows: the circular point-shaped welding head with the diameter less than or equal to 10mm is adopted to carry out ultrasonic welding for 0.5-3s under the conditions that the pressure is 15-50Psi, the power is 1500-6000W and the frequency is 10-60 kHz.
9. A bare cell, wherein the bare cell is prepared by the method of any of claims 1-8.
10. A battery comprising the bare cell of claim 9.
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| CN202010151977.9A CN111341991A (en) | 2020-03-06 | 2020-03-06 | Method for preventing electrode lug from being inserted reversely and reducing battery cell failure |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116014083A (en) * | 2023-02-16 | 2023-04-25 | 江苏正力新能电池技术有限公司 | Manufacturing process of lithium ion battery capable of preventing tab from being reversely inserted and lithium ion battery |
| WO2024077652A1 (en) * | 2022-10-11 | 2024-04-18 | 湖北亿纬动力有限公司 | Cell pack and power battery |
| WO2024083016A1 (en) * | 2022-10-18 | 2024-04-25 | 宁德时代新能源科技股份有限公司 | Shell assembly, battery cell, battery and electric device |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020146620A1 (en) * | 2001-04-06 | 2002-10-10 | Ntk Powerdex, Inc. | Method of joining current collectors in a multi-layer cell |
| CN204885322U (en) * | 2015-08-12 | 2015-12-16 | 东莞市骏卓自动化科技有限公司 | Metal -back power battery assembly line |
| CN206250267U (en) * | 2016-12-27 | 2017-06-13 | 宁德时代新能源科技股份有限公司 | Battery core and secondary cell |
-
2020
- 2020-03-06 CN CN202010151977.9A patent/CN111341991A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020146620A1 (en) * | 2001-04-06 | 2002-10-10 | Ntk Powerdex, Inc. | Method of joining current collectors in a multi-layer cell |
| CN204885322U (en) * | 2015-08-12 | 2015-12-16 | 东莞市骏卓自动化科技有限公司 | Metal -back power battery assembly line |
| CN206250267U (en) * | 2016-12-27 | 2017-06-13 | 宁德时代新能源科技股份有限公司 | Battery core and secondary cell |
Non-Patent Citations (4)
| Title |
|---|
| 曹瑜琦: ""锂电池极耳层叠超声焊温度测量及工艺优化"", 《新技术新工艺》 * |
| 曹瑜琦: ""锂离子动力电池铝极耳超声波焊接工艺研究"", 《新技术新工艺》 * |
| 王波，等: ""热辅助超声波增材制造设备设计与分析"", 《焊接学报》 * |
| 王波，等: ""铝-铜层状复合材料热辅助超声波増材制造方法"", 《机械工程学报》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024077652A1 (en) * | 2022-10-11 | 2024-04-18 | 湖北亿纬动力有限公司 | Cell pack and power battery |
| WO2024083016A1 (en) * | 2022-10-18 | 2024-04-25 | 宁德时代新能源科技股份有限公司 | Shell assembly, battery cell, battery and electric device |
| CN116014083A (en) * | 2023-02-16 | 2023-04-25 | 江苏正力新能电池技术有限公司 | Manufacturing process of lithium ion battery capable of preventing tab from being reversely inserted and lithium ion battery |
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