CN216529234U - Battery structure - Google Patents

Abstract

The utility model belongs to the technical field of batteries and discloses a battery structure. The battery structure comprises a shell, a pole, brazing filler metal and a confluence disc. The utmost point post sets up on the casing, and utmost point post is equipped with the welding region. The solder is attached to the welding area of the pole. The confluence disc is covered on the brazing filler metal, and the brazing filler metal is used for forming precise resistance welding connection between the confluence disc and the pole. The battery structure is not easy to generate dust and other pollution during welding, can be used in a cleaning workshop needing to control dust and temperature and humidity, is not easy to damage welding base metal, and is high in welding strength, high in welding power and not easy to cause insufficient welding.

Description

a battery structure

technical field

The utility model relates to the technical field of batteries, in particular to a battery structure.

Background technique

With the popularization and development of new energy vehicles and electric bicycles, users have put forward higher requirements for the performance of lithium batteries. The small cylindrical cells of traditional 18650 batteries and 21700 batteries can no longer meet the current demand for energy density, so large cylindrical cells came into being. Compared with traditional cylindrical batteries, the performance of large cylindrical batteries is significantly improved, mainly in terms of space utilization, production cost, safety and performance. Because the size of the cylinder is increased from small to large and the number of monomers is small, the actual space utilization rate becomes larger; due to the reduction in the control requirements of the large cylindrical battery on all aspects of the BMS, the use of structural parts and production processes will be reduced, and the cost will be reduced accordingly; There are no concentrated hot spots inside the battery, and the heat is evenly distributed inside; at the same time, the fast charging performance is further improved, and the battery can be charged from 0 to 80% in 15 minutes. When a large cylindrical battery is manufactured, its positive pole needs to be electrically connected to the positive collector, and whether the connection between the positive pole and the positive collector is reliable will directly affect the performance, mission life, production qualification rate and other indicators of the battery.

In the prior art, riveting and ultrasonic welding are generally used to directly electrically connect the positive pole and the busbar. However, riveting is not suitable for the semi-sealed cell structure of a large cylinder. Ultrasonic welding will reduce the thickness of the base metal in the welding area by 50%, resulting in low connection strength. The influence of the diaphragm interference will reduce the welding power and cause virtual welding. In addition, the ultrasonic welding will generate metal chips during the welding process, and the metal chips remaining inside the battery case may easily cause a short circuit inside the battery.

Therefore, there is an urgent need to propose a battery structure that can improve the welding strength and welding power, and is not easy to cause virtual welding to solve the above problems.

Utility model content

The purpose of the utility model is to provide a battery structure, which is not easy to produce dust and other pollution during welding, is not easy to cause damage to the welding base material, has high welding strength, high welding power, and is not easy to cause false welding.

For this purpose, the utility model adopts the following technical solutions:

A battery structure comprising:

case;

a pole, the pole is arranged on the casing, and the pole is provided with a welding area;

solder, the solder is attached to the welding area of the pole;

A busbar, the busbar is covered on the brazing material, and the brazing material is used to form a precise resistance welding connection between the busbar and the pole.

Optionally, the thickness of the solder is 0.2mm-0.3mm.

Optionally, the brazing filler metal is circular, and its diameter is 5mm-7mm.

Optionally, the manifold and the brazing material are arranged concentrically.

Optionally, the solder is aluminum-based solder.

Optionally, a battery cell is provided in the casing, the battery core includes an end surface, and the busbar is attached to the end surface and is electrically connected to the battery core.

Optionally, a sealing insulating member is provided between the pole and the housing.

Optionally, the pole post is riveted to the housing.

Optionally, the material of the pole is aluminum.

Optionally, the material of the busbar is aluminum.

Beneficial effects:

In the utility model, brazing filler metal is placed in the welding area provided by the pole post, and the busbar is welded on the pole post through the brazing filler metal. By using precision resistance welding, high-frequency current is used to generate resistance heat on the surface of the welding material to weld the busbar and pole, which is not easy to produce dust and other pollution, and can be used in clean workshops where dust, temperature and humidity need to be controlled. The welding base metal causes damage, the welding strength is high, the welding power is high, and it is not easy to cause false welding.

Description of drawings

Fig. 1 is the structural schematic diagram 1 of the battery structure provided by the present invention;

2 is a second structural schematic diagram of a battery structure provided by the present invention;

3 is a schematic structural diagram of a positive electrode busbar provided by the present invention;

FIG. 4 is a schematic structural diagram of the battery structure in the welding process provided by the present invention.

In the picture:

100, shell; 200, positive pole; 300, solder; 400, positive collector plate; 500, electrode.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner" and "outer" The orientation or positional relationship indicated by etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, with a specific orientation. Therefore, it should not be construed as a limitation on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed to indicate or imply relative importance. Wherein, the terms "first position" and "second position" are two different positions, and the first feature being "above", "over" and "above" the second feature includes the first feature being "over" the second feature Directly above and diagonally above, or simply means that the first feature is level higher than the second feature. The first feature is "below", "below" and "below" the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature has a lower level than the second feature.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a connectable connection. Detachable connection, or integral connection; may be mechanical connection or electrical connection; may be direct connection, or indirect connection through an intermediate medium, or internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, but should not be construed as a limitation of the present invention.

At present, large cylindrical cells are developing rapidly in the market, and riveting is usually used for the connection between the pole and the busbar, or the contact surface between the pole and the busbar is ultrasonically welded. However, riveting is not suitable for the structure of large cylindrical semi-sealed cells, and ultrasonic welding itself has the disadvantages of inconcentration of energy and poor consistency. Applying it to large cylindrical cells will reduce the thickness of the welding area of the base metal, and it will reduce the thickness of the welding area of the base metal. damage to the material, resulting in low connection strength and unreliable connection. In addition, the area where the sonotrode passes is affected by the misalignment of the winding core and the interference of the diaphragm, resulting in a reduction in the welding power, resulting in a virtual welding. The battery is short-circuited, resulting in a low battery qualification rate and poor safety performance, which cannot be used in workshops with high environmental requirements. The battery structure provided in this embodiment can effectively solve the above problems.

As shown in FIG. 1 , a battery structure provided in this embodiment includes a casing 100 , a pole, a brazing filler metal 300 and a busbar. The pole is arranged on the casing 100, and a welding area is provided thereon. The solder 300 is attached to the welding area of the pole. The busbar is covered on the brazing filler metal 300, and the brazing filler metal 300 is used to form a precise resistance welding connection between the busbar and the pole.

In the above-mentioned battery structure, a welding area is set on the pole, the brazing material 300 is set in the welding area, and the confluence plate is covered on the brazing material 300. By adopting precision resistance welding, the resistance heat generated on the surface of the brazing material 300 by the high-frequency current is used to make the brazing material. 300 melts to realize the electrical connection between the busbar and the pole. By setting the brazing material 300 and using precision resistance welding to realize the connection between the busbar and the pole, it is not easy to generate dust and other pollution, and can be used in workshops that need to control dust, temperature and humidity and other requirements for high environmental cleanliness. In addition, this connection method is not easy to cause damage to the pole and the busbar, the welding power is high, it is not easy to cause false welding, the connection strength is high, and the reliability is strong. The surface is smooth, the operation is simple, and the environmental requirements are not high.

The above-mentioned poles may be positive poles 200 or negative poles, and the busbars may be positive poles 400 or negative poles. The battery structure will be described below by taking the combination of the positive pole 200 and the positive busbar 400 as an example.

Continuing to refer to FIG. 1 , the casing 100 of the battery structure is cylindrical, the material of the casing 100 can be a steel casing or an aluminum casing, a through hole is provided on the end face of the bottom of the casing 100 , and the positive pole 200 passes through the through hole Connected to the bottom of the housing 100 . It can be understood that if the connection between the positive pole 200 and the casing 100 is poor, the positive pole 200 will be dislocated on the casing 100, which will cause the positive pole 200 and the positive bus plate 400 to be detached or misaligned. It will cause the current to not flow smoothly, resulting in battery damage and high scrap rate. In order to keep the relative position of the positive pole 200 and the positive bus plate 400 unchanged, it is necessary to ensure that the relative position of the positive pole 400 and the casing 100 is fixed. Therefore, the positive pole 200 can be fixedly connected to the casing by riveting 100 on.

Further, a sealing insulator may be provided between the positive pole 200 and the casing 100 to block the contact between the positive pole 200 and the casing 100 , thereby preventing the positive pole 200 from being electrically connected to the casing 100 and causing danger. Optionally, the sealing insulating member may be insulating glue.

In this embodiment, the material of the positive pole 200 is aluminum, and in other embodiments, it can also be made of copper or other materials. The welding area is set at the center of the positive pole 200 , and the brazing material 300 is placed on the welding area of the positive pole 200 .

FIG. 2 is a partial structural schematic diagram of the battery structure. It can be seen from FIG. 2 where the brazing filler metal 300 is placed. The setting of the brazing filler metal 300 can realize the connection between the positive electrode pole 200 and the positive electrode busbar 400, and the positive electrode busbar 400 and The weldability of the positive pole 200 reduces the difficulty of welding. Optionally, the brazing filler metal 300 is circular with a diameter of 5mm-7mm, for example, it may be 5mm, 6mm or 7mm. Further, the thickness of the brazing filler metal 300 may be 0.2mm-0.3mm, for example, may be 0.2mm, 0.25mm or 0.3mm. It can be understood that if the diameter of the solder 300 is too large or the thickness is too thick, it will cause waste of materials and increase the production cost. If the thickness is too thin, the reliability of the connection between the positive electrode post 200 and the positive electrode busbar 400 cannot be guaranteed. Of course, in other embodiments, the thickness and diameter of the brazing filler metal 300 can be set according to the size of the battery and the welding requirements, as long as the shape and size of the welding of the positive electrode pole 200 and the positive electrode bus plate 400 can be realized, all of which are described in this application. within the scope of protection.

FIG. 3 is a schematic structural diagram of the positive electrode busbar 400 . The positive electrode busbar 400 and the brazing material 300 are arranged concentrically, and the material of the positive electrode busbar 400 is aluminum. It can be understood that, the positive busbar 400 , the brazing filler metal 300 and the positive pole 200 are arranged concentrically, which can ensure sufficient current intensity.

In the present embodiment, since the material of the positive pole 200 and the positive bus 400 is aluminum, the solder 300 is an aluminum-based solder 300 to ensure that it is similar to the material of the positive pole 200 and the positive collector 400. After welding The conductivity is also similar to ensure that the battery has sufficient conductivity. In other embodiments, the material of the brazing filler metal 300 can be selected according to the welding base metal.

Further, the casing 100 is also provided with a battery cell. The battery core includes end faces, namely a positive terminal face and a negative terminal face. The positive electrode busbar 400 is attached to the positive terminal face and is electrically connected to the positive electrode of the battery cell.

When the battery structure is assembled, the positive pole 200 is passed through the through hole at the bottom of the casing 100 and riveted to the casing 100. A sealing and insulating member is arranged between the positive pole 200 and the casing 100 to avoid electrical connection between the two, and the sealing The insulating member may be a sealing ring. The brazing filler metal 300 is placed in the welding area of the positive electrode pole 200 to ensure that the two are concentrically arranged, and then the positive electrode bus plate 400 is covered on the brazing filler metal 300 to ensure that the positive electrode bus plate 400 and the pole are arranged concentrically. Then, the positive busbar 400 and the positive pole 200 are welded by precision resistance welding. As shown in FIG. 4 , the two electrodes 500 are clamped on the inner side and the outer side of the bottom of the casing 100 respectively, and the resistance welding machine is turned on. The alternating current generates resistance heat on the surface of the material through high-frequency current, and the electrode presses the welding area, thereby realizing the welding of the material. Precision resistance welding is used for welding, the heating time is short and the heat is concentrated, so the heat affected zone is small, and the sealing ring in the shell 100 will not be affected by high temperature. Realize mechanization and automation, suitable for mass production, high production rate and low production cost. For the welding of the positive busbar 400 and the positive pole 200, the production efficiency of precision resistance welding and ultrasonic welding is the same, but the equipment and accessories required for precision resistance welding are low in cost, and can solve the problems caused by ultrasonic welding. Welding and metal chips, etc.

It can be understood that the negative electrode of the battery can be adjusted with reference to the above description of the positive electrode of the battery structure, such as: the negative electrode pole and the negative electrode bus plate are welded, and the negative electrode bus plate is attached to the negative end surface of the cell, and It is electrically connected to the negative pole of the cell.

The battery structure can be applied to a cylindrical battery or a square battery, and the shapes of the positive electrode busbar, the brazing material 300 and the pole can be adjusted according to the structural form of the battery.

Obviously, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, rather than limiting the implementation of the present invention. For those of ordinary skill in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. There is no need and cannot be exhaustive of all implementations here. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present utility model shall be included within the protection scope of the claims of the present utility model.

Claims (10)

1. a battery structure, is characterized in that, comprises: housing (100); a pole, the pole is arranged on the casing (100), and the pole is provided with a welding area; brazing filler metal (300), the brazing filler metal (300) is attached to the welding area of the pole post; A busbar, the busbar is covered on the brazing material (300), and the brazing material (300) is used to form a precision resistance welding connection between the busbar and the pole. 2 . The battery structure according to claim 1 , wherein the brazing filler metal ( 300 ) has a thickness of 0.2 mm to 0.3 mm. 3 . 3. The battery structure according to claim 1, wherein the brazing filler metal (300) is circular, and its diameter is 5mm-7mm. 4. The battery structure according to claim 1, wherein the busbar and the brazing material (300) are arranged concentrically. 5. The battery structure according to claim 1, wherein the solder (300) is an aluminum-based solder. 6. The battery structure according to any one of claims 1-5, characterized in that a battery cell is provided in the casing (100), the battery core includes an end face, and the busbar is attached to the on the end face, and is electrically connected to the cell. 7. The battery structure according to any one of claims 1-5, characterized in that a sealing insulating member is arranged between the pole and the casing (100). 8. The battery structure according to any one of claims 1-5, characterized in that, the pole post is riveted to the casing (100). 9 . The battery structure according to claim 1 , wherein the material of the pole is aluminum. 10 . 10 . The battery structure according to claim 1 , wherein the material of the busbar is aluminum. 11 .

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