CN117810509A

CN117810509A - Battery cell, welding method thereof and battery

Info

Publication number: CN117810509A
Application number: CN202311680332.4A
Authority: CN
Inventors: 王莹辉; 李华; 胡俊洲; 张海波; 廖兴群; 潘党育
Original assignee: Shenzhen Highpower Technology Co Ltd
Current assignee: Shenzhen Highpower Technology Co Ltd
Priority date: 2023-12-08
Filing date: 2023-12-08
Publication date: 2024-04-02

Abstract

The invention provides a battery cell, a welding method thereof and a battery, which aim to solve the problem that the spot welding tension of an anode current collecting plate and a pole group of the existing nickel-metal hydride battery is smaller; according to the invention, the first metal side band is arranged at one end of the positive electrode plate, which is close to the positive electrode current collecting disc, and the first metal side band is welded with the positive electrode current collecting disc, so that the welding tension between the first metal side band and the positive electrode current collecting disc is more than 180N, and the welding tension between the positive electrode current collecting plate and the electrode group is improved.

Description

Battery cell, welding method thereof and battery

Technical Field

The invention relates to the technical field of battery cell welding, in particular to a battery cell, a welding method thereof and a battery.

Background

At present, most of anodes of nickel-hydrogen batteries are manufactured by adopting a mode of sizing a foam nickel pull tab and reserving foam nickel, cathodes are manufactured by adopting a mode of reserving a platinum edge by a steel belt sizing pull tab, battery cell electrode group manufacturing is realized by winding a positive electrode plate and a negative electrode plate and a diaphragm, positive electrode plate and positive electrode current collecting plates are in spot welding by a grinding electrode group, the positive electrode plate and the positive electrode current collecting plates are communicated, foam nickel is filled at the bottom of a steel shell after the positive electrode plates are put into a shell, contact communication between a negative electrode steel belt, a bottom pad foam nickel and the steel shell is realized, battery cell manufacturing is realized by working procedures of rolling grooves, coating openings, alkali injection, spot welding of positive electrode caps, sealing and the like, but the spot welding tension of the positive electrode current collecting plates and the positive electrode group is only 15-50N; therefore, how to overcome the above-mentioned technical problems and drawbacks becomes an important problem to be solved.

Disclosure of Invention

Aiming at the problem that the spot welding tension of the current positive electrode current collecting plate and the current electrode group of the nickel-metal hydride battery is small, the invention provides a battery cell welding method.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the invention provides a battery cell, which comprises a battery cell packaging piece, a pole group, an anode current collecting disc and a cathode current collecting disc, wherein the anode current collecting disc, the pole group and the cathode current collecting disc are sequentially arranged in the battery cell packaging piece, the pole group is formed by winding an anode pole piece, a diaphragm and a cathode pole piece, one end, close to the anode current collecting disc, of the anode pole piece is provided with a first metal sideband, the first metal sideband is connected with the anode current collecting disc, and the cathode pole piece is connected with the cathode current collecting disc.

Optionally, a through hole is formed in the center of the positive electrode current collecting disc, a plurality of first grooves are formed in the periphery of the positive electrode current collecting disc, first welding teeth are arranged on the side walls of the first grooves, and the first welding teeth extend along the direction perpendicular to the positive electrode current collecting disc and close to the electrode group.

Optionally, the positive pole piece includes positive current collector, be close to on the positive current collector the one end of negative pole current collecting plate is attached with positive active material layer, be close to on the positive current collector the other end of positive current collecting plate is first blank district, first blank district is connected with first metal sideband, first metal sideband with the welding of positive current collecting plate's first welding tooth.

Optionally, a plurality of second recesses have been seted up to the periphery of negative pole current collecting plate, all be provided with the second welding tooth on the lateral wall of second recess, the second welding tooth is followed perpendicularly the negative pole current collecting plate and is close to the direction extension of utmost point group.

Optionally, the negative electrode plate includes a negative electrode current collector, a negative electrode active material layer is attached to one end of the negative electrode current collector, which is close to the positive electrode current collecting plate, and a second empty area is formed at the other end of the negative electrode current collector, which is close to the negative electrode current collecting plate, and is welded with the second welding teeth of the negative electrode current collecting plate.

Optionally, the surface that the negative pole current collecting plate deviates from the utmost point group is formed with the orientation the bellied boss of casing, the boss includes first boss and second boss, first boss is in the center of negative pole current collecting plate forms, the second boss is in the periphery of first boss forms, first boss with the second boss all with the bottom welding of electric core package.

Optionally, the device further comprises a first welding boss and a second welding boss, wherein the surface of the first boss, which faces away from the pole group, is provided with the first welding boss protruding towards the shell; the surface of the second boss, which is away from the pole group, is provided with a second welding boss protruding towards the shell, and the first welding boss and the second welding boss are welded with the bottom of the battery cell packaging piece.

Optionally, the device further comprises an H-shaped structural member, the H-shaped structural member comprises an H-shaped connecting piece, a first connecting boss and a second connecting boss, a first arc-shaped groove is formed at one end of the H-shaped connecting piece opposite to the through hole, the surface of the H-shaped connecting piece, which is close to one end of the positive electrode current collecting disc, is provided with the first connecting boss protruding towards the positive electrode current collecting disc, the first connecting boss is arranged at two sides of the first arc-shaped groove, and the first connecting boss is connected with one side, which is away from the electrode group, of the positive electrode current collecting disc; the surface of the H-shaped connecting sheet far away from one end of the positive electrode current collecting disc is provided with a second connecting boss protruding towards the positive electrode current collecting disc, the second connecting bosses are arranged on two sides of the second arc-shaped groove, and the H-shaped connecting sheet is bent and connected with the top of the battery cell packaging piece through the second connecting boss.

The invention also provides a battery cell welding method for preparing the battery cell, which comprises the following steps:

welding the first blank area and the first metal sideband on the positive current collector in an ultrasonic roll welding mode;

welding the first welding teeth of the positive electrode current collecting disc and the first metal side band in a spot welding mode;

welding the second welding teeth of the negative electrode current collecting disc and the second metal side band in a spot welding mode;

the positive electrode current collecting disc, the electrode group and the negative electrode current collecting disc are sequentially arranged inside the battery cell packaging piece, the first boss and the second boss are welded with the bottom of the battery cell packaging piece in a spot welding mode at the bottom of the battery cell packaging piece, an H-shaped structural member is placed above the positive electrode current collecting disc, and then a battery cell is manufactured through rolling grooves, coating openings, alkali injection, spot welding of a positive electrode cap and sealing.

In still another aspect, the invention provides a battery, which is prepared by the welding method of the battery cell.

According to the battery cell welding method provided by the invention, the first metal side band is arranged at one end of the positive pole piece, which is close to the positive current collecting disc, and the first metal side band has high hardness, and the welding tension between the first metal side band and the positive current collecting disc can reach more than 180N through welding the first metal side band and the positive current collecting disc, so that the welding tension between the positive current collecting piece and the pole group is improved.

Drawings

Fig. 1 is a schematic structural diagram of a battery cell according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a positive current collector in a battery cell according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of an H-shaped structural member in a battery cell according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of an anode current collector and an H-shaped structural member in a battery cell according to an embodiment of the present invention;

FIG. 5 is a schematic front view of the structure of the positive current collector and the H-shaped structure in the battery cell according to an embodiment of the present invention;

fig. 6 is a schematic front view of a negative current collecting plate in a battery cell according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a negative current collecting plate in a battery cell according to an embodiment of the present invention;

fig. 8 is a schematic side view of a negative current collecting plate in a battery cell according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of a positive electrode plate in a battery cell according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of a negative electrode tab in a battery cell according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of a connection between a cell package and a negative current collecting disc in a cell produced by a grinding electrode group method according to the prior art;

fig. 12 is a schematic structural diagram of connection between a battery cell package and a negative electrode current collecting disc in a battery cell produced by a roll welding method according to an embodiment of the present invention;

FIG. 13 is a schematic diagram of the prior art provided for the movement of the positive pole piece electrons in a cell produced by way of a grind set;

FIG. 14 is a schematic view of the movement of the positive electrode tab in a battery cell produced by a roll welding method according to an embodiment of the present invention;

reference numerals in the drawings of the specification are as follows:

1-an anode current collecting disc; 11-a first groove; 12-a first welding tooth; 13-through holes; 2-a negative electrode current collecting disc; 21-a second groove; 22-second welding teeth; 23-a first boss; 24-a second boss; 25-a first welding boss; 26-a second welding boss; 3-H type structural member; 31-H type connecting piece; 32-a first arc-shaped groove; 33-a first connection boss; 34-a second arcuate slot; 35-a second connection boss; 4-a positive pole piece; 41-positive electrode current collector; 42-a positive electrode active material layer; 43-first blank area; 44-a first metallic sideband; 5-a negative electrode piece; 51-negative electrode current collector; 52-a negative electrode active material layer; 53-a second blank area; 6-cell package; 7-membrane.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects solved by the invention more clear, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "side", "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of description and to simplify the description, and do not indicate or imply that the apparatus or element in question must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present invention, it should be noted that, unless explicitly stated and limited otherwise, the term "connected" should be interpreted broadly, and for example, it may be a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

As shown in fig. 1, in one embodiment, the present invention provides a battery core, which includes a battery core package 6, a pole group, a positive current collecting disc 1 and a negative current collecting disc 2, wherein the positive current collecting disc 1, the pole group and the negative current collecting disc 2 are sequentially disposed inside the battery core package 6, the pole group is formed by winding a positive pole piece 4, a diaphragm 7 and a negative pole piece 5, one end of the positive pole piece 4, which is close to the positive current collecting disc 1, is provided with a first metal sideband 44, the first metal sideband 44 is connected with the positive current collecting disc 1, and the negative pole piece 5 is connected with the negative current collecting disc 2.

In an embodiment, the battery cell is a nickel-hydrogen battery cell, the nickel-hydrogen battery cell comprises a battery cell packaging piece 6, a pole group, an anode current collecting disc 1 and a cathode current collecting disc 2, and the anode current collecting disc 1 is made of cold-rolled carbon steel; the cathode current collecting disc 2 is made of cold-rolled carbon steel.

At present, the positive pole piece 4 of the nickel-hydrogen battery is mostly manufactured by adopting a mode of sizing a foam nickel pull piece and reserving foam nickel, the negative pole piece 5 is manufactured by adopting a mode of reserving a platinum edge by a steel belt sizing pull piece, the positive pole piece 4, the negative pole piece 5 and a diaphragm 7 are wound to manufacture a battery cell pole group, the positive pole piece 4 and the positive pole current collecting disc 1 are communicated by grinding the pole group to spot-weld the positive pole current collecting disc 1, the foam nickel is filled at the bottom of the battery cell packaging piece 6 after the battery cell is put into a shell, the contact and communication between the negative pole current collector 51 and the bottom foam nickel and the battery cell packaging piece 6 are realized, the battery cell manufacturing is realized by the working procedures of rolling grooves, coating openings, alkali injection, spot-welding the positive pole cap, sealing and the like, but the spot-welding tension of the positive pole current collecting disc 1 and the pole group is only 15-50N.

However, the foam nickel material is softer, the strength of the foam nickel material is not enough with that of the positive current collecting disc 1, and the foam nickel material is easy to fry and weld, and the first metal side band 44 is arranged at one end of the positive electrode pole piece 4, which is close to the positive current collecting disc 1, so that the hardness of the first metal side band 44 is high, the strength of the foam nickel material is high when the foam nickel material is directly welded with the positive current collecting disc 1 in a spot welding manner, and the welding tension of the first metal side band 44 and the positive current collecting disc 1 is more than 180N, so that the welding tension between the positive current collecting disc 1 and a pole group is improved.

As shown in fig. 2 and fig. 4-5, in an embodiment, a through hole 13 is formed in the center of the positive current collecting plate 1, a plurality of first grooves 11 are formed in the periphery of the positive current collecting plate 1, and first welding teeth 12 are disposed on the side walls of the first grooves 11, and the first welding teeth 12 extend along a direction perpendicular to the positive current collecting plate 1 and close to the electrode group.

Specifically, the material of the positive electrode current collecting disc 1 is cold-rolled carbon steel; the outside of the positive electrode current collecting disc 1 is provided with a nickel plating layer, and the thickness of the nickel plating layer is 0.0012-0.002mm;

the periphery of the positive electrode current collecting disc 1 is provided with first grooves 11, and the number of the first grooves 11 is 2, 3, 4, 5, 6, 7, 8, 9 or 10; the first grooves 11 are uniformly distributed on the periphery of the positive electrode current collecting disc 1.

In a preferred embodiment, the number of the first grooves 11 is 4, the width of the first grooves 11 is 3±0.05mm, and the length of the first grooves 11 is 4.5±0.2mm.

The thickness direction of the first welding teeth 12 is the thickness direction of the first welding teeth 12 along the length direction of the battery cell, and the thickness of the first welding teeth 12 is 0.5 plus or minus 0.05mm; the width of the first welding teeth 12 is 0.5 plus or minus 0.05mm along the length direction of the first groove 11 and the length direction of the first welding teeth 12; the width of the first welding teeth 12 is 0.15 + -0.05 mm.

The first welding teeth 12 are used for welding with the first metal sidebands 44 in a spot welding mode, so that the positive electrode pole piece 4 and the positive electrode current collecting disc 1 are connected into a whole; the spot welding has low cost and firm welding.

As shown in fig. 9, in an embodiment, the positive electrode sheet 4 includes a positive electrode current collector 41, a positive electrode active material layer 42 is attached to one end of the positive electrode current collector 41 near the negative electrode current collecting disc 2, a first blank area 43 is formed on the other end of the positive electrode current collector 41 near the positive electrode current collecting disc 1, the first blank area 43 is connected with the first metal sideband 44, and the first metal sideband 44 is welded with the first welding teeth 12 of the positive electrode current collecting disc 1.

In an embodiment, the positive electrode piece 4 includes a positive electrode current collector 41, and the material of the positive electrode current collector 41 is one of nickel foam, nickel-plated steel strip and copper mesh; in a preferred embodiment, the positive electrode current collector 41 is made of foam nickel.

In one embodiment, the first metal strap 44 is made of one of pure nickel strap or nickel-plated steel strap; in a preferred embodiment, the first metal strap 44 is made of pure nickel strap.

Specifically, at least one side surface of the positive electrode current collector 41 is attached with a positive electrode active material layer 42 which does not completely cover the foam nickel substrate layer, and the positive electrode active material layer 42 is prepared by mixing a positive electrode active material, a conductive agent, an additive, a thickener, a binder and pure water to prepare slurry; the positive electrode sheet 4 is formed by unreeling, prepressing, sizing, drying, rolling and cutting.

In the sizing process, along the width direction of the positive current collector 41, the positive active material layer 42 is coated at one end close to the negative current collecting disc 2, and one end, close to the positive current collecting disc 1, of the positive current collector 41 is a first blank area 43; the first blank area 43 is welded with the first metal side band 44 in an ultrasonic roll welding mode, the first metal side band 44 is positioned at one end of the pole group close to the positive electrode current collecting plate 1, a first welding tooth 12 is arranged at one side of the positive electrode current collecting plate 1 close to the pole group, and the first metal side band 44 is connected with the first welding tooth 12 of the positive electrode current collecting plate 1 in a welding mode to connect the positive electrode current collecting plate 1 with the positive electrode pole piece 4; the welding power is 4 KW-5 KW; the welding time was 5.+ -.2 milliseconds.

Further, the end of the first metal sideband 44 near the positive electrode current collecting disc 1 is not in contact with the negative electrode plate 5 and the diaphragm 7, so that the phenomenon that the first welding teeth 12 are connected with the negative electrode plate 5 to cause short circuit is avoided during welding.

Specifically, the width of the first blank area 43 is 4±0.5mm; the length of the first blank area 43 is 440+/-1 mm; the width of the first metal sideband 44 is 2.0+/-0.2 mm; the length of the first metal sideband 44 is 440+/-1 mm; the thickness of the first metallic tape 44 is 0.12mm.

The width of the first empty region 43 is 4+/-0.5 mm; the length of the first blank area 43 is 440+/-1 mm; the width of the first metal sideband 44 is 2.0+/-0.2 mm; the length of the first metal sideband 44 is 440+/-1 mm; the thickness of the first metal strap 44 is 0.12mm;

in one embodiment, the first blank area 43 and the first metal strap 44 are welded in a laminated manner, the overlapping area is a welding area, the width of the welding area is 2.5±0.5mm, and the length of the welding area is 440±1mm.

In another embodiment, the first blank area 43 is in contact with the first metal strap 44, and welded at an edge portion thereof, and the first blank area 43 and the first metal strap 44 are connected.

Welding the first blank area 43 and the first metal sideband 44 in an ultrasonic roll welding mode, wherein the welding power is 300W-600W; the welding time is 12+/-3 seconds.

According to the invention, an active substance is not filled at one end of the positive electrode plate 4, so that a pure nickel strip or a nickel-plated steel strip is roll-welded on the foam nickel of the positive electrode current collector 41, and when the battery cell is assembled, the upper end edge of the electrode group is not compacted, and a gap is reserved, so that the gas at the upper part of the electrode group is fast in recombination speed when the battery cell is charged and discharged, and the charging internal pressure of the battery cell is reduced.

As shown in fig. 6 to 8, in an embodiment, the periphery of the anode current collecting plate 2 is provided with a plurality of second grooves 21, and the side walls of the second grooves 21 are provided with second welding teeth 22, and the second welding teeth 22 extend along a direction perpendicular to the anode current collecting plate 2 and close to the electrode group.

Specifically, the cathode current collecting disc 2 is made of cold-rolled carbon steel; the outside of the negative electrode current collecting disc 2 is provided with a nickel plating layer, and the thickness of the nickel plating layer is 0.0012-0.002mm;

the periphery of the negative electrode current collecting disc 2 is provided with second grooves 21, and the number of the second grooves 21 is 2, 3, 4, 5, 6, 7, 8, 9 or 10; the second grooves 21 are uniformly distributed on the periphery of the negative electrode current collecting disc 2.

In two preferred embodiments, the number of the second grooves 21 is 4, the width of the second grooves 21 is 3±0.05mm, and the length of the second grooves 21 is 8.5±0.2mm.

The thickness direction of the second welding teeth 22 is the thickness direction of the second welding teeth 22 along the length direction of the battery cell, and the thickness of the second welding teeth 22 is 0.5 plus or minus 0.05mm; the width of the second welding teeth 22 is 0.5 plus or minus 0.05mm along the length direction of the second groove 21 and the length direction of the second welding teeth 22; the width of the second welding teeth 22 is 0.15 + -0.05 mm.

The second welding teeth 22 are used for welding with the second metal side band in an ultrasonic roll welding manner, so that the negative electrode plate 5 and the negative electrode current collecting disc 2 are connected into a whole.

As shown in fig. 10, in an embodiment, the negative electrode tab 5 includes a negative electrode current collector 51, a negative electrode active material layer 52 is attached to one end of the negative electrode current collector 51 near the positive electrode current collecting disc 1, and a second empty space 53 is formed at the other end of the negative electrode current collector 51 near the negative electrode current collecting disc 2, where the second empty space 53 is welded with the second welding teeth 22 of the negative electrode current collecting disc 2.

In an embodiment, the negative electrode tab 5 includes a negative electrode current collector 51, and the negative electrode current collector 51 is one of a copper mesh or a steel mesh; in a preferred embodiment, the negative current collector 51 is a steel mesh.

Specifically, a negative electrode active material layer 52 which does not completely cover the steel mesh substrate layer is attached to at least one side surface of the negative electrode current collector 51, and the negative electrode active material layer 52 is prepared by mixing a negative electrode active material, a conductive agent, an additive and a solvent to prepare a negative electrode active slurry; the negative electrode plate 5 is formed by unreeling, prepressing, sizing, drying, rolling and cutting.

In the sizing process, along the width direction of the negative electrode current collector 51, the negative electrode active material layer 52 is coated at one end close to the positive electrode current collector plate 1, one end, close to the positive electrode current collector plate 1, of the negative electrode current collector 51 is provided with a second empty space 53, the second empty space 53 is positioned at one end, close to the negative electrode current collector plate 2, of the electrode group, one side, close to the electrode group, of the negative electrode current collector plate 2 is provided with second welding teeth 22, and the second empty space 53 is connected with the second welding teeth 22 of the negative electrode current collector plate 2 in a welding manner to connect a negative electrode current collector plate with a negative electrode pole piece 5; the welding power is 1.5 KW-2.0 KW; the welding time was 5.+ -.2 milliseconds.

Further, the end of the second metal edge or the second blank 53 near the cathode current collecting disc 2 is not in contact with the anode plate 4 and the separator 7, so that the phenomenon that the second welding teeth 22 are connected with the anode plate 4 to cause short circuit is avoided during welding.

As shown in fig. 6 to 8, in an embodiment, a boss protruding toward the housing is formed on a surface of the anode current collecting plate 2 facing away from the electrode group, the boss includes a first boss 23 and a second boss 24, the first boss 23 is formed at a center of the anode current collecting plate 2, the second boss 24 is formed at an outer periphery of the first boss 23, and both the first boss 23 and the second boss 24 are welded to a bottom of the cell package 6.

Specifically, after the electrode group is welded to the positive current collecting disc 1 and the negative current collecting disc 2, the electrode group, the positive current collecting disc 1 and the negative current collecting disc 2 are put into the battery cell package 6 together, a boss protruding towards the shell is formed on the surface of the negative current collecting disc 2, which faces away from the electrode group, the boss comprises a first boss 23 and four second bosses 24, the four second bosses 24 are uniformly distributed on the periphery of the first boss 23, and after the electrode group is put into a shell, the first boss 23 and the four second bosses 24 are respectively welded with the bottom of the battery cell package 6 through spot welding, wherein the welding power is 3.5 KW-4 KW; the soldering time is 5±2 milliseconds, thereby firmly connecting the pole group and the cell package 6.

The thickness of the boss is 1.3+/-0.05 mm; within the thickness range, the welding of the negative electrode current collecting disc 2 and the bottom of the battery cell packaging piece 6 can be guaranteed, and the tensile force reaches more than 100N; and the excessive thickness of the boss can be avoided, and the energy density of the battery cell is reduced.

As shown in fig. 6-8, in an embodiment, further comprising a first welding boss 25 and a second welding boss 26, a surface of the first boss 23 facing away from the pole group is formed with the first welding boss 25 protruding toward the housing; the surface of the second boss 24 facing away from the pole group is provided with a second welding boss 26 protruding towards the housing, and the first welding boss 25 and the second welding boss 26 are welded with the bottom of the battery cell package 6.

Specifically, the first welding boss 25 and the second welding boss 26 are respectively located on the surfaces of the first boss 23 and the second boss 24, after the first welding boss 25 and the four second welding bosses 26 are put into the shell, the first welding boss 25 and the four second welding bosses 26 are respectively spot-welded with the bottom of the battery cell package 6, and the welding power is 3.5 KW-4 KW; the soldering time is 5±2 milliseconds, thereby firmly connecting the pole group and the cell package 6.

The thickness of the first welding boss 25 and the second welding boss is 1.3 + -0.05 mm; within the thickness range, the welding of the negative electrode current collecting disc 2 and the bottom of the battery cell packaging piece 6 can be ensured, the tensile force reaches more than 100N, and the negative electrode current collecting disc is not damaged; and the excessive thickness of the boss can be avoided, and the energy density of the battery cell is reduced.

As shown in fig. 3-5, in an embodiment, the H-shaped structural member 3 further includes an H-shaped connecting piece 31, a first connecting boss 33 and a second connecting boss 35, one end of the H-shaped connecting piece 31 opposite to the through hole 13 is provided with a first arc-shaped groove 32, the surface of the H-shaped connecting piece 31 near one end of the positive current collecting plate 1 is formed with the first connecting boss 33 protruding towards the positive current collecting plate 1, the first connecting boss 33 is disposed at two sides of the first arc-shaped groove 32, and the first connecting boss 33 is connected with one side of the positive current collecting plate 1 facing away from the electrode group; the surface of one end of the H-shaped connecting piece 31, which is far away from the positive electrode current collecting disc 1, is provided with a second connecting boss 35 protruding towards the positive electrode current collecting disc 1, the second connecting boss 35 is arranged on two sides of the second arc-shaped groove 34, and the H-shaped connecting piece 31 is bent and connected with the top of the battery cell packaging piece 6 through the second connecting boss 35.

Specifically, the first arc groove 32 includes a straight groove and an arc groove, the arc groove is opposite to the through hole 13, and the radius of the arc groove is greater than or equal to the radius of the through hole 13, two sides of the straight groove are connected with two ends of the arc groove, the first connection boss 33 protrudes towards the positive current collecting plate 1, the first connection boss 33 is connected with one side of the positive current collecting plate 1, which is away from the pole group, and the H-shaped connection piece 31 is bent and connected with the top of the battery cell package 6 through the second connection boss 35; the H-shaped structural member 3 is used for protecting the pole group and preventing the pole group from being in contact with the battery cell packaging piece 6 to cause short circuit.

welding the first blank area 43 and the first metal sideband 44 on the positive electrode current collector 41 in an ultrasonic roll welding mode;

welding the first welding teeth 12 of the positive electrode current collecting disc 1 and the first metal side band 44 by spot welding;

welding the second welding teeth 22 of the negative electrode current collecting disc 2 and the second metal side band by spot welding;

the positive electrode current collecting disc 1, the electrode group and the negative electrode current collecting disc 2 are sequentially arranged inside the battery cell packaging piece 6, the first boss 23 and the second boss 24 are welded with the bottom of the battery cell packaging piece 6 in a spot welding mode at the bottom of the battery cell packaging piece 6, and the positive electrode current collecting disc 1 is welded with the top of the battery cell packaging piece 6 in a spot welding mode at the top of the battery cell packaging piece 6.

Specifically, the positive electrode plate 4 and the negative electrode plate 5 are prepared before welding,

the preparation method of the positive electrode plate 4 comprises the following steps:

preparing a positive electrode active material slurry: mixing the positive electrode active material, the conductive agent, the additive and the solvent according to a certain proportion to prepare positive electrode active material slurry;

the positive electrode sheet 4 is formed by unreeling, prepressing, sizing, drying, rolling and cutting.

In the sizing process, the positive electrode active material layer 42 is coated on one end close to the negative electrode current collecting disc 2 along the width direction of the positive electrode current collecting body 41, one end, close to the positive electrode current collecting disc 1, of the positive electrode current collecting body 41 is provided with a first blank area 43, the first blank area 43 and the first metal side band 44 are welded in an ultrasonic roll welding mode, and the welding power is 300-600W; the welding time is 12+/-3 seconds.

The preparation method of the negative electrode plate 5 comprises the following steps:

preparing a negative electrode active material slurry: mixing the anode active material, the conductive agent, the additive and the solvent according to a certain proportion to prepare anode active material slurry;

the negative electrode plate 5 is formed by unreeling, prepressing, sizing, drying, rolling and cutting.

In the sizing process, the negative electrode active material layer 52 is coated on one end, close to the positive electrode current collecting disc 1, along the width direction of the negative electrode current collector 51, and one end, close to the negative electrode current collecting disc 2, of the negative electrode current collector 51 is a second empty space 53.

The cell welding method comprises the following steps:

step one: winding the positive electrode plate 4, the diaphragm 7 and the negative electrode plate 5 to form the electrode group, wherein in the winding process, one end of the first metal sideband 44, which is close to the positive electrode current collecting disc 1, is not contacted with the negative electrode plate 5 and the diaphragm 7, and one end of the second blank 53, which is close to the negative electrode current collecting disc 2, is not contacted with the positive electrode plate 4 and the diaphragm 7;

step two: the first metal side band 44 and the first welding teeth 12 of the positive electrode current collecting disc 1 are connected with the positive electrode current collecting disc 1 and the positive electrode pole piece 4 through spot welding; the welding power is 4 KW-5 KW; the welding time is 5+/-2 milliseconds; the second blank area 53 and the second welding teeth 22 of the negative electrode current collecting disc 2 are connected with a negative electrode current collecting piece and a negative electrode pole piece 5 in a spot welding mode; the welding power is 1.5 KW-2.0 KW; the welding time was 5.+ -.2 milliseconds.

Step three: placing the positive electrode current collecting disc 1, the electrode group and the negative electrode current collecting disc 2 into the battery cell packaging piece 6 together, and after the battery cell packaging piece is put into a shell, respectively spot-welding the first boss 23 and the four second bosses 24 with the bottom of the battery cell packaging piece 6, wherein the welding power is 3.5 KW-4 KW; the welding time is 5+/-2 milliseconds, and the tensile force reaches more than 100N, so that the pole group is firmly connected with the bottom of the battery cell packaging piece 6.

Fig. 11 is a schematic structural diagram of a cell produced by grinding a pole group in the prior art, specifically, a cell package 6 connected with a cathode current collecting disc 2; as shown in fig. 11, the cell package 6 and the anode current collecting disc 2 are connected by a pole grinding group, and no welding tension exists between the cell package 6 and the anode current collecting disc 2, so that the cell package 6 and the anode current collecting disc 2 are easy to loosen, and the internal resistance of the cell is increased after loosening.

Fig. 12 is a schematic structural diagram of a battery cell produced by a roll welding method according to an embodiment of the present invention, specifically, a battery cell package 6 and a negative electrode current collecting plate 2; as shown in fig. 12, the battery cell package 6 and the negative electrode current collecting disc 2 are connected in a matched manner in a roll welding manner, the welding between the battery cell package 6 and the negative electrode current collecting disc 2 is firm, the battery cell package 6 and the negative electrode current collecting disc 2 are not loosened, and the internal resistance of the battery cell is relatively stable.

Step four, placing an H-shaped structural member 3 above the positive electrode current collecting disc 1, and then manufacturing a nickel-hydrogen cell through rolling a groove, coating a mouth, injecting alkali, spot welding a positive electrode cap and sealing;

the positive electrode cap is welded with the positive electrode current collecting disc 1 and the positive electrode cap, and the welding tension is more than 180N, so that the welding performance of the positive electrode current collecting disc 1, the electrode group and the battery cell packaging piece 6 is improved.

Fig. 13 is a schematic structural diagram of a cell produced by grinding a pole group in the prior art, specifically, a cell package 6 connected with a positive current collecting disc 1; arrows in the figure indicate paths through which electrons flow; as shown in fig. 13, by connecting the cell package 6 to the positive current collecting plate 1 by way of a grind electrode group, a path through which half of electrons in the positive electrode tab 4 flow is long, resulting in a large internal resistance of the cell.

Fig. 14 is a schematic structural diagram of a battery cell produced by a roll welding method according to an embodiment of the present invention, specifically, a battery cell package 6 is connected to a positive current collecting plate 1; arrows in the figure indicate paths through which electrons flow; as shown in fig. 14, the battery cell package 6 is connected with the positive current collecting plate 1 by a roll welding method, so that the paths of electrons flowing through the positive electrode plate 4 are shorter, and the internal resistance of the battery cell can be effectively reduced.

In some embodiments, the battery housing is a square housing, a cylindrical housing, a prismatic housing, or other irregular housing.

The invention is further illustrated by the following examples.

Example 1

The preparation method of the positive electrode plate comprises the following steps:

cobalt-coated nickel hydroxide serving as a positive electrode active material, titanium dioxide serving as a conductive agent, ytterbium trioxide, sodium carboxymethyl cellulose serving as an additive, polytetrafluoroethylene (60%) and pure water in a mass ratio of 96:1:1:0.05: and (3) uniformly mixing the materials in a ratio of 0.6 to 28 to prepare positive electrode slurry, coating the positive electrode slurry on the surface of a positive electrode current collector, wherein the width of a first blank area is 4+/-0.2 mm, the length of the first blank area is 440+/-1 mm, and then forming a positive electrode plate by adopting drying, rolling and cutting.

Welding the first blank area by adopting an ultrasonic roll welding mode and a first metal sideband nickel strap by adopting an ultrasonic roll welding mode, wherein the width of the first metal sideband is 2.5+/-0.2 mm, and the length of the first metal sideband is 440+/-1 mm; the welding power of the first metal sideband and the first blank area is 0.3-0.6 KW; the welding time is 9-15 seconds; the preparation method of the negative electrode plate comprises the following steps:

mixing negative electrode active material alloy powder, conductive agent yttrium oxide, graphite, additive sodium carboxymethyl cellulose, SBR (48 percent) and pure water according to the mass ratio of 100:2:0.7:0.1:1.6:15, uniformly mixing to prepare anode active material slurry; and coating the surface of the negative electrode current collector, wherein the width of the second blank area is 2.5+/-0.2 mm, the length of the first blank area is 510+/-1 mm, and then forming the negative electrode plate by adopting drying, rolling and cutting.

The cell welding method comprises the following steps:

step one: winding the positive pole piece, the diaphragm and the negative pole piece to form a pole group;

step two: welding the first metal side band with the first welding teeth of the positive electrode current collecting disc; the welding power is 4KW to 5KW; the welding time is 3-7 milliseconds; welding the second blank area with second welding teeth of the negative electrode current collecting disc; the welding power is 1.5-2 KW; the welding time is 3-7 milliseconds.

Step three: placing the positive electrode current collecting disc, the electrode group and the negative electrode current collecting disc into a battery cell packaging piece together, and after the battery cell packaging piece is put into a shell, respectively carrying out spot welding on the first boss and the four second bosses and the bottom of the battery cell packaging piece, wherein the welding power is 3.5-4 KW; the welding time is 3-7 milliseconds;

placing an H-shaped structural member above the positive electrode current collecting disc, and then manufacturing a nickel-hydrogen battery cell through rolling a groove, coating a port, injecting alkali, spot welding a positive electrode cap and sealing;

and fifthly, selecting the battery cell with the capacity gear between 12800 and 12900 mA.h.

Example 2

Example 2 is used to illustrate the disclosed cell and its soldering method, including most of the operating steps in example 1, which are different in that: and selecting a battery cell with the capacity gear between 12900 and 13000 mA.h.

Example 3

Example 3 is used to illustrate the disclosed cell and its soldering method, including most of the operating steps in example 1, which are different in that: and selecting a battery cell with the capacity gear of 13000-13100 mA.h.

Comparative example 1

cobalt-coated nickel hydroxide serving as a positive electrode active material, titanium dioxide serving as a conductive agent, ytterbium trioxide, sodium carboxymethyl cellulose serving as an additive, polytetrafluoroethylene (60%) and pure water in a mass ratio of 96:1:1:0.05: uniformly mixing 0.6:28 according to a mass ratio to prepare anode slurry, coating the anode slurry on the surface of an anode current collector, wherein the width of a first blank area is 4+/-0.2 mm, the length of the first blank area is 440+/-1 mm, and then forming an anode sheet by adopting drying, rolling and cutting.

The cell welding method comprises the following steps:

step two: the positive electrode group compacts the foam nickel by grinding.

Step three: and placing the positive electrode current collecting disc and the electrode group into the steel shell after spot welding.

Comparative example 2 is used to illustrate the disclosed cell and its method of soldering, including most of the operating steps of example 1, with the following differences: and selecting a battery cell with the capacity gear between 12900 and 13000 mA.h.

Comparative example 3

Comparative example 3 is used to illustrate the disclosed cell and its method of soldering, including most of the operating steps of example 1, with the following differences: and selecting a battery cell with the capacity gear of 13000-13100 mA.h.

Performance testing

1) Internal resistance test: charging with 0.2C current for 5H hours first; a battery full state; then testing the internal resistance of the battery by using a battery internal resistance tester of a daily-arranged BT3536 model; and the values are recorded.

2) Discharge temperature test: a. discharge to a voltage of 1.0V with 0.2C at room temperature; charging with 0.2C current for 7 hours; standing for 1 hour; discharging the mixture to 1.0V at 0.2C; the change of the battery surface temperature was recorded by a japanese graphic GL model 240 data acquisition instrument. b. Discharge to a voltage of 1.0V with 0.2C at room temperature; charging with 0.5C current for 2.8 hours; standing for 1 hour; discharging the mixture to 1.0V at 0.5C; the change of the battery surface temperature was recorded by a japanese graphic GL model 240 data acquisition instrument. c. Discharging to voltage 1.0V at room temperature with 0.2C respectively; charging with 1C current for 1.4 hours; standing for 1 hour; discharging the 1C to 1.0V; the change of the battery surface temperature was recorded by a japanese graphic GL model 240 data acquisition instrument.

3) 0 degree charge and discharge test: placing the battery in a high-low temperature box of the model Especk GSU-24V; charging at 0.1C for 12 hours at 0 ℃, and standing for 1 hour; then, the voltage was discharged to 1.0V by 0.2C, and the process voltage was recorded by a Japanese graphic GL240 model data acquisition instrument.

4) 25 degree charge-discharge curve: placing the battery in a high-low temperature box of the model Especk GSU-24V; charging at 25deg.C for 12 hr at 0.1C, and standing for 1 hr; then, the voltage was discharged to 1.0V by 0.2C, and the process voltage was recorded by a Japanese graphic GL240 model data acquisition instrument.

5) 40 degree charge-discharge curve: placing the battery in a high-low temperature box of the model Especk GSU-24V; charging at 40 ℃ for 12 hours at 0.1 ℃, and standing for 1 hour; then, the voltage was discharged to 1.0V by 0.2C, and the process voltage was recorded by a Japanese graphic GL240 model data acquisition instrument.

6) Welding tension between positive electrode current collecting piece and positive electrode cap: adopting a HLSY-1000 type tensile testing machine; test speed: 50mm/min; mode selection: a force value slow-down judging mode; the maximum force value is tested.

Test results:

as is apparent from the above table, the nickel-hydrogen battery manufactured according to the welding method of the example of the present invention has significantly reduced internal resistance from 4.1mΩ to 3.5mΩ of the comparative example, by 14.6%, and has no reduction in temperature safety characteristics, as compared with the comparative example. In addition, in the nickel-metal hydride battery prepared by the welding method, as the first metal side band is welded at one end of the positive pole piece, which is close to the positive current collecting disc, and the first metal side band is welded with the positive current collecting disc, the welding tension of the first metal side band and the positive current collecting disc is more than 180N, so that the welding tension between the positive current collecting disc and the pole group is improved.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.

Claims

1. The utility model provides an electric core which characterized in that: the battery cell packaging part, the pole group, the positive current collecting disc and the negative current collecting disc are arranged in sequence, the positive current collecting disc, the pole group is formed by winding a positive pole piece, a diaphragm and a negative pole piece, a first metal sideband is arranged at one end, close to the positive current collecting disc, of the positive pole piece, the first metal sideband is connected with the positive current collecting disc, and the negative pole piece is connected with the negative current collecting disc.

2. The cell of claim 1, wherein: the center of positive plate collector is formed with the through-hole, a plurality of first recesses have been seted up to positive plate collector's periphery, all be provided with first welding tooth on the lateral wall of first recess, first welding tooth is followed perpendicularly positive plate collector and be close to the orientation of utmost point group extends.

3. A cell according to claim 2, characterized in that: the positive pole piece comprises a positive pole current collector, a positive pole active material layer is attached to one end, close to the negative pole current collecting disc, of the positive pole current collector, a first blank area is arranged at the other end, close to the positive pole current collecting disc, of the positive pole current collector, the first blank area is connected with a first metal sideband, and the first metal sideband is welded with the first welding teeth of the positive pole current collecting disc.

4. A cell according to claim 2, characterized in that: the periphery of negative pole current collection dish has seted up a plurality of second recesses, all be provided with the second welding tooth on the lateral wall of second recess, the second welding tooth is followed perpendicularly the negative pole current collection dish is close to the direction extension of utmost point group.

5. The cell of claim 4, wherein: the negative electrode plate comprises a negative electrode current collector, a negative electrode active material layer is attached to one end, close to the positive electrode current collecting disc, of the negative electrode current collector, a second blank area is arranged at the other end, close to the negative electrode current collecting disc, of the negative electrode current collector, and the second blank area is welded with the second welding teeth of the negative electrode current collecting disc.

6. The cell of claim 1, wherein: the surface that the negative electrode current collecting disc deviates from the polar group is formed with the orientation the bellied boss of casing, the boss includes first boss and second boss, first boss is in the center of negative electrode current collecting disc forms, the second boss is in the periphery of first boss forms, first boss with the second boss all with the bottom welding of electric core package.

7. The cell of claim 1, wherein: the surface of the first boss, which is away from the pole group, is provided with the first welding boss which protrudes towards the shell; the surface of the second boss, which is away from the pole group, is provided with a second welding boss protruding towards the shell, and the first welding boss and the second welding boss are welded with the bottom of the battery cell packaging piece.

8. A cell according to claim 2, characterized in that: the H-shaped structure comprises an H-shaped connecting piece, a first connecting boss and a second connecting boss, a first arc-shaped groove is formed at one end of the H-shaped connecting piece opposite to the through hole, the surface of the H-shaped connecting piece, which is close to one end of the positive electrode current collecting disc, is provided with the first connecting boss protruding towards the positive electrode current collecting disc, the first connecting boss is arranged at two sides of the first arc-shaped groove, and the first connecting boss is connected with one side, which is away from the pole group, of the positive electrode current collecting disc; the surface of the H-shaped connecting sheet far away from one end of the positive electrode current collecting disc is provided with a second connecting boss protruding towards the positive electrode current collecting disc, the second connecting bosses are arranged on two sides of the second arc-shaped groove, and the H-shaped connecting sheet is bent and connected with the top of the battery cell packaging piece through the second connecting boss.

9. A welding method of an electric core is characterized in that: a method for preparing a cell according to any one of claims 1-8, comprising the steps of:

10. A battery, characterized in that: the battery is prepared by the welding method of the battery cell of claim 9.