Connecting structure of lithium battery plate lugs and poles and manufacturing method thereof

Abstract

The invention discloses a connecting structure of lithium battery plate lugs and poles. The connecting structure comprises lugs of a multi-layer foil sheet structure formed by superposing a plurality of layers of foil sheets, wherein the plate lugs comprise a positive electrode plate lug and a negative electrode plate lug; the plate lugs are pressed and packaged by virtue of buffer foil sheet machinery; butt-joint side foil sheets of the buffer foil sheets packaging the plate plugs are superposed and pressed; the plate lugs and the buffer foil sheets are mechanically pressed for pre-connected by virtue of ultrasonic welding; poles are arranged at single-layer sides of the buffer foil sheets; the poles, the plate plugs and the buffer foil sheets are connected by welding; and the adopted welding mode is a filling type stirring friction spot-welding mode. The connecting structure of lithium battery plate lugs and poles manufactured by the manufacturing method disclosed by the invention has the advantages of good reliability and conductivity, capacity of improving the battery consistency, beautiful appearance, and relatively strong processing suitability.

Description

technical field [0001] The invention relates to the technical field of connection between a tab and a pole of a lithium battery, in particular to a connection structure between a tab and a pole of a multilayer foil structure of a lithium battery and a manufacturing method thereof. Background technique [0002] In the main structure of most lithium batteries currently on the market, ultra-thin electrolytic metal foils are used as positive and negative electrode conductors. Choose copper foil and aluminum foil with small internal resistance and good ductility. Among them, the positive electrode adopts ultra-thin electrolytic aluminum foil, and the negative electrode adopts ultra-thin electrolytic copper foil. The multi-layer foil structure of the lead-out part of the positive and negative electrodes is called tab. In the manufacturing process of lithium batteries, the connection between the tabs and the poles of the multilayer foil structure is a key difficulty. In the prio...

AI Technical Summary

Problems solved by technology

The punching and riveting process may result in impurities such as metal shavings residues, electrode material chips, etc., i.e. excess

During the charging and discharging process of the battery, these excess substances may pierce the separator, resulting in a short circuit or a micro short circuit, resulting in a decrease in the working capacity of the battery or even failure

(2) Since the riveted joint is mechanically fitted, the inherent gap between the plates will cause the electrolyte to penetrate into the joint, and the surface of the bus plate material will be oxidized through the long-term charge and discharge process, resulting in a rapid increase in contact resistance, thereby forming a larger battery. resistance, reducing the charge and discharge performance and life of the battery

Although the traditional bolt riveting fastening process can achieve a firm connection between tabs and poles with greater thickness, as mentioned above, the connection structure and manufacturing method of lithium battery tabs and poles in the prior art seriously affect the lithium battery. Battery performance reliability and service life

However, the existing ultrasonic welding process is limited by its own shortcomings, and cannot well solve the welding problem between the tab with more layers of foil structure and the thicker pole.

In short, the existing connection technology of tabs and poles severely limits the design and manufacture of lithium battery structures due to its own shortcomings, thus affecting the development and application of lithium batteries.

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