CN205050913U - Lithium battery module is with compound busbar and lithium battery module - Google Patents

Abstract

The utility model relates to a lithium battery module is with compound busbar and lithium battery module belongs to lithium ion battery module technical field. The utility model discloses a lithium battery module includes the anodal section of aluminium, copper negative pole section with compound busbar, anodal section of aluminium and copper negative pole section braze joint. The utility model discloses a set up the brazing filler metal layer and braze the anodal section of aluminium with copper negative pole section and be in the same place between the anodal section of aluminium and copper negative pole section, with busbar and utmost point post perhaps extremely the welding between the ear all become the welding between the material of the same race, has avoided contact resistance between the different metal material to increase and has taken place phenomenon such as electrochemical corrosion easily.

Description

Composite conductive bar for lithium battery module and lithium battery module

technical field

The utility model relates to a composite conductive row for a lithium battery module and a lithium battery module, belonging to the technical field of lithium ion battery modules.

Background technique

With the rapid development of the power battery market, the demand for power sources is increasing. Since the capacity, voltage, and current of a single battery cannot meet the requirements of a power battery power supply, the power supply is generally combined into a battery module through a single battery, and then the battery module is assembled into a power supply. Since the voltage and current required by the power supply are very high, it is usually necessary to combine many cells in series and parallel to realize the assembly of the battery module and the power supply.

The series connection and parallel connection of batteries are usually carried out through conductive bars. Generally, the conductive bars are fixed to the battery poles or tabs through nuts or screws to realize the connection between the conductive bars and the battery poles or tabs. The Chinese utility model patent with the authorized announcement number CN201369355Y (authorized announcement date is December 23, 2009) discloses a new type of conductive strip for batteries. The conductive strip is made of an integral copper sheet, and the two ends of the copper sheet are folded It is formed into a ring shape matching the shape of the cylindrical section of the pole, and the bending part is fastened to the cylindrical section of the pole by a screw. In this connection method, the nut or screw will become loose due to external vibration, gradually increasing the contact resistance between the conductive bar and the battery, thereby reducing the output voltage and current of the battery, and reducing the cycle life of the battery.

In order to avoid the above problems, more and more manufacturers consider using welding instead of screw or nut connection, that is, the conductive row of copper or other materials is welded to the positive pole or lug and the negative pole or lug respectively. However, since the positive pole or tab of the lithium-ion battery is made of aluminum, and the negative pole or tab is made of copper, when the batteries are connected in series, the positive pole of the battery needs to be connected to the negative pole of another battery. During welding, the conductive row will be different from at least one material of the positive electrode and the negative electrode, which will result in a large contact resistance between different metals, and electrochemical corrosion will easily occur at the welding place.

Utility model content

The purpose of the utility model is to provide a composite conductive bar for lithium battery modules to solve the problems of large contact resistance and easy corrosion in the prior art when the conductive bar is welded to tabs. The purpose of the utility model is also to provide a lithium battery module using the composite conductive row.

In order to achieve the above purpose, the technical scheme of the composite conductive row for the lithium battery module of the present invention is as follows:

A composite conductive row for a lithium battery module, comprising an aluminum positive pole segment, a copper negative pole segment, and a solder layer arranged between the aluminum positive pole segment and the copper negative pole segment.

The aluminum positive pole segment has a positive pole segment groove for inserting the positive pole tab, and the copper negative pole segment has a negative pole segment groove for inserting the negative pole tab. Inserting the tabs into the grooves before welding can improve the firmness of the welding, and also increase the contact area between the tabs and the conductive bar, which is beneficial to reduce the contact resistance between the conductive bar and the tabs.

Measuring through holes are provided at the bottoms of the positive pole segment groove and the negative pole segment groove. The gap between the tab and the conductive bar can be measured by measuring the through hole, and then it can be judged whether the gap will affect the subsequent welding quality. Moreover, the welding gap between the tab and the conductive bar can be detected after welding, and then treatment measures can be taken to avoid the decrease in electrical connection reliability or the increase in release resistance caused by virtual welding or excessive weld seam.

The surface of the composite conducting bar is plated with nickel or tin. The reflectivity of the conductive row to the laser light during laser welding is reduced.

An identification hole is arranged on one of the aluminum positive pole segment and the copper negative pole segment. In order to facilitate the identification of the positive and negative pole segments of the plated conductive bar.

The aluminum positive pole segment has a positive pole connecting portion, the copper negative pole segment has a negative pole connecting portion, and the positive pole connecting portion overlaps with the negative pole connecting portion.

The technical scheme of the lithium battery module of the present utility model is as follows:

A lithium battery module, comprising a lithium ion battery and a composite conductive row, the composite conductive row including an aluminum positive section, a copper negative section, and a solder layer arranged between the aluminum positive section and the copper negative section, the aluminum positive section It is welded with the positive tab of the lithium ion battery, and the copper negative segment is welded with the negative tab of the lithium ion battery.

The aluminum positive pole segment has a positive pole segment groove for inserting the positive pole tab, and the copper negative pole segment has a negative pole segment groove for inserting the negative pole tab. Inserting the tabs into the grooves before welding can improve the firmness of the welding, and also increase the contact area between the tabs and the conductive bar, which is beneficial to reduce the contact resistance between the conductive bar and the tabs.

Measuring through holes are provided at the bottoms of the positive pole segment groove and the negative pole segment groove. The gap between the tab and the conductive bar can be measured by measuring the through hole, and then it can be judged whether the gap will affect the subsequent welding quality. Moreover, the welding gap between the tab and the conductive bar can be detected after welding, and then treatment measures can be taken to avoid the decrease in electrical connection reliability or the increase in release resistance caused by virtual welding or excessive weld seam.

The surface of the composite conducting bar is plated with nickel or tin. The reflectivity of the conductive row to the laser light during laser welding is reduced.

An identification hole is arranged on one of the aluminum positive pole segment and the copper negative pole segment. In order to facilitate the identification of the positive and negative pole segments of the plated conductive bar.

The utility model sets a solder layer between the aluminum positive pole section and the copper negative pole section and brazes the aluminum positive pole section and the copper negative pole section together, so that when the lithium battery is connected in series, the aluminum positive pole section and the positive pole column or ear Welding, the copper negative section is welded to the negative pole or tab, and the welding between the conductive row and the pole or tab is turned into a welding between the same material, which avoids the increase of contact resistance between different metal materials. Large and prone to electrochemical corrosion and other phenomena.

Description of drawings

FIG. 1 is a schematic structural view of an embodiment of a lithium battery module of the present invention;

FIG. 2 is a schematic structural diagram of the composite conductive row in FIG. 1 .

detailed description

Embodiments of the lithium battery module of the present utility model:

As shown in Figure 1-2, the battery module of the present invention is a lithium-ion battery module, including a lithium-ion soft pack battery 1 and a composite conductive bar 2, and the lithium-ion battery includes an aluminum positive pole tab 11 and a copper negative pole Tabs 12. In this embodiment, the number of lithium-ion soft-pack batteries is eight, and every four batteries are arranged sequentially in such a way that the positive tabs face the positive tabs, and the negative tabs face the negative tabs to form a battery arrangement unit. Two battery arrangement units are placed side by side in such a way that the positive pole tabs and the negative pole tabs are opposite to form a module pole group, and each side of the module pole group has four positive pole tabs and four negative pole tabs arranged side by side.

The composite conductive row includes an aluminum positive pole segment 21, a copper negative pole segment 22, and a solder layer 212 arranged between the aluminum positive pole segment and the copper negative pole segment. The aluminum positive pole segment is an aluminum plate or an aluminum alloy plate, and the aluminum plate or an aluminum alloy plate By bending upwards and arching, the positive electrode segment grooves with the notches facing downward are formed on the plate surface. The number of positive electrode segment grooves is four, and the extending direction is perpendicular to the length direction of the plate, and they are arranged parallel to each other. Aluminum positive electrodes Both ends of the section have a positive connecting portion extending in the horizontal direction; the copper negative section is a copper plate, the material is red copper T2, the copper plate is bent upwards and arched to form a negative section groove with the notch facing downward, and the negative section groove The number is four, the extension direction is perpendicular to the plate length direction, and they are arranged parallel to each other, and the two ends of the copper negative electrode segment have negative electrode connection parts extending in the horizontal direction. The positive connection part overlaps with the negative connection part, the positive connection part is at the bottom, the negative connection part is at the top, and a solder layer is arranged between the upper surface of the positive connection part and the lower surface of the negative connection part, so that the aluminum positive segment and the copper negative segment The solder layers are overlapped and brazed together, and the melting point of the solder layer is higher than 200° C., so as to avoid melting the solder layer due to the high temperature generated when the conductive bar is welded to the tab in the later stage.

The four positive pole lugs and the four negative pole lugs on one side of the module pole group are connected by composite conductive bars. The tabs are respectively inserted into the corresponding negative electrode segment grooves and connected by welding. The four positive tabs on the other side of the module pole group are connected with the positive parallel conductive bar 3, and the four negative tabs are connected with the negative parallel conductive bar 4. The positive parallel conductive bar and the negative parallel conductive bar are respectively connected to the positive section The structure is the same as that of the negative section, the positive tab is inserted into the groove on the positive parallel conductive bar and welded, and the negative tab is inserted into the groove on the negative parallel conductive bar and welded.

The groove bottoms of the positive pole groove and the negative pole groove are provided with measuring through holes 222. In this embodiment, the tops of the upward protrusions formed by bending and arching the positive pole groove and the negative pole groove are provided with "U"-shaped notch, the "U"-shaped notch constitutes the measurement through hole, the depth of the notch is greater than the plate thickness of the corresponding positive pole segment or negative pole segment, so that the positive pole lug or negative pole lug inserted into the groove A part can be exposed from the gap, and it can be observed whether the gap between the top of the tab and the bottom of the groove is too large, and then it can be judged whether the welding between the tab and the composite conductive bar is firm. Similarly, the same notch as the above-mentioned measuring through hole structure is also provided on the positive parallel conductive row and the negative parallel conductive row.

The welding connections in this embodiment all adopt laser welding. In order to reduce the reflectivity of the conductive row to the laser during laser welding, the composite conductive row is coated with a layer of nickel coating or tin coating. The thickness of the coating reduces the laser reflectivity of the metal surface. to the minimum. Since the colors of the positive electrode segment and the negative electrode segment are relatively similar after being plated, a small round hole is provided on the negative electrode segment as the identification hole 221 for easy identification during installation.

When installing the battery module of this embodiment, the lithium-ion soft-pack batteries are first arranged into battery arrangement units in order, and the two battery arrangement units are placed side by side to form a module pole group, and a composite conductive row, a positive parallel conductive row, The negative parallel conductive bar connects the positive pole tab and the negative pole tab in the module pole group to form a battery module, and the positive parallel conductive bar and the negative parallel conductive bar form the positive pole and the negative pole of the battery module respectively.

In other embodiments of the battery module of the present invention, no groove for the positive electrode segment is provided on the positive electrode segment, no groove for the negative electrode segment is provided on the negative electrode segment, the positive electrode lug is directly welded to the positive electrode segment, and the negative electrode lug is directly welded to the negative electrode paragraph.

In other embodiments, the measuring through hole is a circular through hole disposed at the bottom of the groove of the positive electrode segment and the groove of the negative electrode segment. In other embodiments, no measuring through hole is provided on the groove of the positive pole segment and the groove of the negative pole segment, and the tabs are inserted into the bottom of the groove as much as possible to ensure the welding effect.

In other embodiments, the identification hole is arranged on the positive pole segment. It is also possible not to set the identification hole, and of course, it is also possible not to set the plating layer, and only rely on the colors of the aluminum plate and the copper plate to distinguish the positive electrode segment and the negative electrode segment.

In other embodiments, the number of grooves on the positive pole segment and the negative pole segment is set according to the number of tabs of the battery in the battery module.

The embodiment of the composite conductive row for the lithium battery module of the present invention is completely consistent with the structure of the composite conductive row in the above-mentioned embodiment of the lithium battery module, and will not be repeated here. In addition, various alternative structures of the composite conductive row in the above-mentioned embodiments of the lithium battery module are also applicable to the embodiments of the composite conductive row for the lithium battery module of the present invention.

Claims (10)

1. A composite conductive bar for a lithium battery module, characterized in that it comprises an aluminum positive section (21) and a copper negative section (22), and the aluminum positive section is connected to the copper negative section by brazing. 2. The composite conductive bar for lithium battery modules according to claim 1, wherein the aluminum positive section has a positive section groove for inserting the positive tab, and the copper negative section has a negative tab for the negative pole. Insert the negative segment into the groove. 3. The composite conductive bar for lithium battery modules according to claim 2, characterized in that, the bottoms of the grooves of the positive electrode section and the negative electrode section are both provided with measuring through holes (222). 4. The composite conductive bar for lithium battery modules according to claim 1, characterized in that, the surface of the composite conductive bar is plated with nickel plating or tin plating. 5 . The composite conductive bar for lithium battery modules according to claim 4 , wherein an identification hole ( 221 ) is provided on one of the aluminum positive section and the copper negative section. 6. The composite conductive bar for lithium battery modules according to claim 1, wherein the aluminum positive section has a positive connection part, the copper negative section has a negative connection part, and the positive connection part and the negative connection part are overlapped. . 7. A lithium battery module, comprising a lithium ion battery and a composite conductive row, characterized in that the composite conductive row includes an aluminum positive section (21), a copper negative section (22), and the aluminum positive section and the copper negative section Brazing connection, the aluminum positive segment is welded to the positive tab of the lithium-ion battery, and the copper negative segment is welded to the negative tab of the lithium-ion battery. 8. The lithium battery module according to claim 7, wherein the aluminum positive segment has a positive segment groove for inserting the positive tab, and the copper negative segment has a negative segment for inserting the negative tab groove. 9 . The lithium battery module according to claim 8 , characterized in that, the bottoms of the positive electrode segment groove and the negative electrode segment groove are both provided with measuring through holes ( 222 ). 10. The lithium battery module according to claim 7, wherein the surface of the composite conductive row is plated with a nickel coating or a tin coating, and one of the aluminum positive section and the copper negative section is provided with an identification hole (221 ).