Large cylindrical lithium battery convex spot welding structure negative collector plate

Abstract

The utility model discloses a convex point welding structure negative collector plate of a large cylindrical lithium battery. The convex point welding structure negative collector plate comprises a resistance welding needle, a battery cell, a collector plate, a steel shell, a resistance welding lower electrode, a circular convex point structure and an elliptical convex point structure, the current collecting plates are divided into a positive current collecting plate and a negative current collecting plate, and the negative current collecting plate comprises a negative current collecting plate I with salient points, a negative current collecting plate II with round salient points and a negative current collecting plate III with elliptical salient points. According to the utility model, the welding area of the cathode collector plate is designed into a structure with salient points, so that the pseudo soldering rate of a resistance welding spot bottom is reduced, the welding area of spot bottom welding strength is increased, the internal resistance of the battery is reduced to achieve the purpose of low charging and discharging temperature rise, the safety performance is improved, and high-multiplying-power charging and discharging can be realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to lithium battery negative current collection disc technical field especially relates to a big cylindrical lithium battery projection welding structure negative current collection disc. BACKGROUND

[0002] The existing cylindrical steel shell lithium battery full tab structure, negative current collection disc and shell bottom are connected through resistance welding point bottom form, and the negative current collection disc is fixed through only one welding spot, so that the welding area is small, the overcurrent capacity is low, and the virtual welding condition is prone to occur, which leads to the increase of internal resistance, the high temperature rise and the influence on the safety performance of the battery. UTILITY MODEL CONTENTS

[0003] Based on the technical problems existing in the background art, the utility model provides a big cylindrical lithium battery projection welding structure negative current collection disc, the center point bottom welding position of the negative current collection disc is designed as a projection form, the projection structure can be a circular projection, an elliptical projection or other projection forms, the projection can weld multiple welding spots in one welding cycle, the production efficiency is high, there is no influence of shunting, the welding strength is high, the welding area is large, and the abnormal conditions of virtual welding of the point bottom and large internal resistance caused by small area are improved.

[0004] The utility model discloses a big cylindrical lithium battery projection welding structure negative current collection disc, including resistance welding needle, electric core, current collection disc, steel shell, resistance welding lower electrode, circular projection structure and elliptical projection structure;

[0005] The current collection disc is divided into positive current collection disc and negative current collection disc, and the negative current collection disc includes negative current collection disc one with projection design, negative current collection disc two with circular projection design and negative current collection disc three with elliptical projection design;

[0006] The steel shell material is SPCC;

[0007] The negative current collection disc is circular;

[0008] The welding position of the negative current collection disc and the electric core is two concaves, which is more closely attached to the electric core without gap, so that the abnormal condition of explosion during welding is prevented;

[0009] The negative current collection disc is provided with two elliptical notches and two circular notches, so that the electrolyte can be infiltrated during liquid injection, and the weight reduction effect is achieved;

[0010] The negative current collection disc material is T2, and the center point bottom welding position is in the form of projection, and the projection structure can be a circular projection or an elliptical projection;

[0011] The material of the resistance welding needle is alumina copper, and the material of the resistance welding lower electrode is copper;

[0012] The projection welding can simultaneously weld multiple welding points in one welding cycle, has high production efficiency and no influence of shunting, has high welding strength and large welding area, the current density of the projection welding is concentrated at the projection, the large current density can use small current for welding and reliably form multiple small molten cores, the position of the projection of the projection welding is accurate, the size is consistent, the welding strength of each point is uniform, and the welding quality is reliable.

[0013] The welding method of the negative current collector disc comprises the following steps:

[0014] S1: the negative electrode end of the battery is welded with the negative current collector disc two with a round projection design or the negative current collector disc three with an oval projection design, the positive electrode end is welded with the positive current collector disc, and the positive electrode end is sleeved with an insulating piece and high-temperature adhesive tape and then enters the steel shell;

[0015] S2: after entering the steel shell, the round projection structure or the oval projection structure of the negative current collector disc is tightly attached to the bottom of the steel shell;

[0016] S3: after entering the steel shell, the battery is penetrated by a resistance welding needle, and under the action of the electrode pressure, pre-pressing time, welding time, welding current and pressure maintaining time of the resistance welding machine, the negative current collector disc one with the projection design is crushed and fused with the bottom of the shell to form multiple small molten cores, so that the welding purpose is achieved;

[0017] S4: subsequent production processes of the battery are carried out.

[0018] The negative current collector disc welding area is designed as a structure with a projection, the virtual welding rate of the resistance welding point bottom is reduced, the welding strength and welding area of the point bottom are increased, the battery internal resistance is reduced, the purpose of low charging and discharging temperature rise is achieved, the safety performance is improved, and large-ratio charging and discharging can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a structural schematic view of the utility model;

[0020] Figure 2 It is an enlarged view of the A structure of the utility model;

[0021] Figure 3 It is a structural schematic view of the negative current collector disc with a round projection design in the utility model;

[0022] Figure 4 It is a structural schematic view of the round projection structure in the utility model;

[0023] Figure 5 It is a structural schematic view of the negative current collector disc with an oval projection design in the utility model;

[0024] Figure 6 It is a structural schematic view of the oval projection structure in the utility model.

[0025] Figure: 1, resistance welding needle; 2, battery cell; 3, negative current collector with convex point design; 4, steel shell; 5, resistance welding lower electrode; 6, negative current collector with round point convex point design; 7, round convex point structure; 8, negative current collector with elliptical convex point design; 9, elliptical convex point structure. DETAILED DESCRIPTION

[0026] The utility model will be further described below in combination with specific embodiments. EMBODIMENT

[0027] Reference Figures 1-6 In the embodiment, a large cylindrical lithium battery convex welding structure negative current collector is provided, which comprises a resistance welding needle 1, a battery cell 2, a current collector, a steel shell 4, a resistance welding lower electrode 5, a round convex point structure 7, and an elliptical convex point structure 9;

[0028] The current collector is divided into a positive current collector and a negative current collector, and the negative current collector comprises a negative current collector with convex point design 3, a negative current collector with round point convex point design 6, and a negative current collector with elliptical convex point design 8;

[0029] The steel shell 4 is made of SPCC;

[0030] The negative current collector is round;

[0031] The welding position of the negative current collector and the battery cell 2 is provided with two grooves, which is more closely attached to the battery cell 2 without gap, preventing abnormal explosion during welding;

[0032] The negative current collector is provided with two elliptical notches and two round notches, which facilitates the infiltration of electrolyte during liquid injection and achieves the effect of weight reduction;

[0033] The negative current collector is made of T2, and the center point bottom welding position is in the form of convex point, which can be round convex point or elliptical convex point;

[0034] The resistance welding needle 1 is made of aluminum oxide copper, and the resistance welding lower electrode 5 is made of copper;

[0035] The convex point welding can simultaneously weld multiple welding points in one welding cycle, which is high in production efficiency and has no influence of shunt, high in welding strength and large in welding area, the current density of the convex point welding is concentrated at the convex point, a smaller current can be used for welding due to the large current density, and multiple smaller molten cores can be reliably formed, the position of the convex point of the convex point welding is accurate, the size is consistent, the welding strength of each point is uniform, and the welding quality is reliable.

[0036] The welding method of the negative current collector comprises the following steps:

[0037] S1: the negative electrode end of the battery cell 2 is welded with the negative electrode current collector plate one 3 with a round dot bump design or with the negative electrode current collector plate three 8 with an oval bump design, the positive electrode end of the battery cell 2 is welded with the positive electrode current collector plate, and the positive electrode end is sleeved with an insulating piece and high-temperature adhesive tape and then is inserted into the steel shell 4;

[0038] S2: after being inserted into the steel shell 4, the negative electrode current collector plate round bump structure 7 or the oval bump structure 9 is tightly attached to the bottom of the steel shell 4;

[0039] S3: after being inserted into the steel shell 4, the battery cell 2 is inserted into the resistance welding needle 1, and the negative electrode current collector plate with the bump design is pressed and crushed and fused together with the bottom of the shell under the action of the electrode pressure, pre-pressing time, welding time, welding current and pressure maintaining time of the resistance welding machine, a plurality of small fusion nuclei are formed, and the welding purpose is achieved;

[0040] S4: the subsequent production process of the battery is performed.

[0041] As can be seen from the above large cylindrical lithium battery bump welding structure negative current collector plate, the bottom welding position of the center point of the negative electrode current collector plate is designed in the form of a bump, the bump structure can be a round bump or an oval bump or other bump forms, the bump can weld a plurality of welding points in one welding cycle, the production efficiency is high, there is no influence of shunting, the welding strength is high, the welding area is large, and the abnormality of the small area of the point bottom virtual welding and the large internal resistance caused by the high temperature rise during charging and discharging is improved.

[0042] In the embodiment, the steel shell material is SPCC nickel-plated, the shell bottom thickness is 0.7mm, the negative electrode current collector plate material is T2, the outer diameter is φ38.5mm, the raw material thickness is 0.3mm, the bump height is 0.1mm, the number of the round bump structure 7 is 33, the number of the oval bump structure 9 is 11, the center welding position diameter is φ5mm, the battery cell 2 is sleeved with an insulating piece and high-temperature adhesive tape after being welded with the positive and negative electrode current collector plates, is inserted into the steel shell 4, and is inserted into the resistance welding needle 1, the resistance bump welding is adopted to weld the negative electrode current collector plate and the bottom of the shell, a plurality of small fusion nuclei are formed at the bump position, and the welding strength and the welding area are improved.

[0043] In the embodiment, the negative electrode current collector plate welding area is designed in the form of a structure with a bump, the resistance welding point bottom virtual welding rate is reduced, the point bottom welding strength and welding area are increased, the battery internal resistance is reduced, the purpose of low temperature rise during charging and discharging is achieved, the safety performance is improved, and large rate charging and discharging is achieved.

[0044] The above is only a preferred specific implementation manner of the present application, but the protection scope of the present application is not limited to this, any skilled person in the art can make equivalent replacement or change according to the technical scheme and the application concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A large cylindrical lithium battery stud welding structure negative current collecting disc, characterized in that, It comprises resistance welding needle (1), electric core (2), current collector, steel shell (4), resistance welding lower electrode (5), circular convex point structure (7) and oval convex point structure (9); The current collector is divided into positive current collector and negative current collector, the negative current collector comprises negative current collector one (3) with convex point design, negative current collector two (6) with circular point convex point design and negative current collector three (8) with oval convex point design; The steel shell (4) is made of SPCC; The negative current collector is circular; The welding position of the negative current collector and the electric core (2) is two concave grooves; The negative current collector is provided with two oval notches and two circular notches; The negative current collector is made of T2, and the center point bottom welding position is in the form of convex point; The material of the resistance welding needle (1) is alumina copper, and the material of the resistance welding lower electrode (5) is copper.

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