Assembly process of cylindrical lithium-ion cell

Abstract

The invention discloses an assembly process of a cylindrical lithium-ion cell. The assembly process comprises the steps of (1), ultrasonically flattening two ends of a winding core; (2), wrapping two ends of the winding core with bottom adhesive tapes; (3), inserting the winding core into a shell; (4), welding a combined body of a flow collection plate and a cover plate on two ends of the winding core; (5), bending a flow collection plate lug; (6), bending the cover plate; (7), forming a lug; (8), embedding the cover plate; and (9), welding the cover to the shell through laser. The assembly process of the cylindrical lithium-ion cell is standard and normal in process; due to adoption of the combination of the flow collection plate and the cover plate, the combined cover plate is welded to the two ends of the winding core, so that the time for shaping the lug is shortened; due to the adoption of a welding manner of ultrasonically flattening and welding two ends through laser, the winding core is inserted into the shell, and then two ends of the winding core are welded, so that the bending and abrasion of the winding core plug are reduced; the yield of subsequent periphery welding is improved, thereby ensuring that the product performance is safer and more reliable.

Description

technical field [0001] The invention relates to an automatic assembly process of a cylindrical lithium-ion battery after the winding of a winding core is completed, in particular to an assembly process of a cylindrical lithium-ion battery. Background technique [0002] With the increasing scarcity of petroleum energy and the approaching energy crisis, lithium-ion batteries, as a new type of energy, have attracted more and more attention. In 1977, Professor Goodenough of the University of Texas in the United States first reported the lithium iron phosphate material and applied it to the production of lithium batteries. In recent years, with the unremitting efforts of scientific researchers, high-performance lithium-ion batteries have been successfully produced. Although lithium-ion batteries are superior to traditional batteries in terms of consistency, cycle performance, power density, and energy storage performance, how to further improve the discharge capacity under high ...

AI Technical Summary

Problems solved by technology

The traditional battery assembly process is as follows (1): Winding completed - the bottom of the core is covered with glue - the core is put into the shell - the gasket is placed - the negative tab is welded to the battery cover - the positive tab is welded - the tab is shaped - the cover is put into the shell first and then Welding and shaping the tabs, because the tabs are long and thin, and the contact surface with the winding core is small, it is easy to cause the tabs to hit the wall, resulting in a short circuit of the winding core; (2): Winding completed - the bottom of the core is coated - add a pad Slice and fix - Pre-shape the positive tab - Weld the battery cover - Weld the positive tab - 90° shaping of the battery cover - Shaping the tab before capping - Pressing the battery and core - The core is integrated into the shell - Closing the cover, this process is carried out first The tabs are put into the shell after shaping. Although the failure rate of the winding core is reduced to a certain extent, the process is cumbersome and the controllability of the process is low, which affects the production efficiency.

At the same time, the battery cover and the winding core are not completely pressed in these two processes. During the capping process, the force of the cap will lead to the entire winding core along the tabs, causing wrinkles inside the winding core and increasing the internal thickness. After the liquid, the winding core will swell and even cause safety problems

[0004] As the requirements for battery capacity are getting higher and higher, the ratio of the size of the winding core to the internal size of the shell is also getting larger and larger, and the requirements for the tabs are becoming more and more stringent, so that the assembly process such as entering the case follows the existing process flow , the difficulty of completion increases, and the number of defective products increases, especially problems such as poor shape of tabs, bumping of tabs, internal folds of batteries, etc.

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