EP-4742429-A1 - A SYSTEM AND A METHOD FOR MANUFACTURING AN ELECTRODE ASSEMBLY

EP4742429A1EP 4742429 A1EP4742429 A1EP 4742429A1EP-4742429-A1

Abstract

A system for manufacturing an electrode assembly is provided, wherein the electrode assembly includes a plurality of unit electrode cells stacked on one another, each of the plurality of unit electrode cells having a unit electrode tab, and wherein the electrode assembly has a main body portion and a tab portion, the tab portion including a plurality of unit electrode tabs protruding from the main body portion. The system comprises: a welding part configured to weld the plurality of unit electrode tabs by applying vibration force; a tab guide for collecting the plurality of unit electrode tabs to supply the collected unit electrode tabs to the welding part for welding; and a tab fixing block configured to hold and press the plurality of unit electrode tabs collected by the tab guide, such that the vibration force applied by the welding part is not transmitted to the main body portion of the electrode assembly.

Inventors

CHOI, JIN HYEONG
HONG, JONG HYUK
KIM, MIN HYUNG
LEE, GYU SUN

Assignees

LG Energy Solution, Ltd.

Dates

Publication Date: 20260513
Application Date: 20241107

Claims (12)

A system for manufacturing an electrode assembly, wherein the electrode assembly includes a plurality of unit electrode cells stacked on one another, each of the plurality of unit electrode cells having a unit electrode tab, and wherein the electrode assembly has a main body portion and a tab portion, the tab portion including a plurality of the unit electrode tabs protruding from the main body portion, the system comprising: a welding part configured to weld the plurality of unit electrode tabs by applying vibration force; a tab guide for collecting the plurality of unit electrode tabs to supply the collected unit electrode tabs to the welding part for welding; and a tab fixing block configured to hold and press the plurality of unit electrode tabs collected by the tab guide, such that the vibration force applied by the welding part is not transmitted to the main body portion of the electrode assembly.
The system of claim 1, wherein the tab fixing block includes two separate pieces being configured to change an interval therebetween, and wherein the tab fixing block is configured to hold and press the plurality of unit electrode tabs positioned in the interval between the two pieces during operation of the welding part.
The system of claim 1 or 2, wherein the tab fixing block is positioned between the tab guide and the welding part.
The system of any one of the preceding claims, wherein the tab guide includes two separate parts configured to make a relative movement with respect to each other, so as to guide and collect the plurality of unit electrode tabs interposed therebetween.
The system of any one of the preceding claims, wherein the welding part includes two separate portions configured to make a relative movement with respect to each other, and wherein the welding part is configured to perform vibration welding by making a relative movement between the two portions while the collected unit electrode tabs are interposed therebetween.
The system of claim 5, wherein the two portions of the welding part are respectively a horn and an anvil, and the relative movement between the two portions is made in a horizonal direction.
The system of any one of the preceding claims, further comprising: a plate on which the main body portion of the electrode assembly is to be placed; and a pusher configured to press the main body portion of the electrode assembly placed on the plate against the plate, so as to hold the electrode assembly during the welding operation by the welding part.
A method for manufacturing an electrode assembly, wherein the electrode assembly includes a plurality of unit electrode cells stacked on one another, each of the plurality of unit electrode cells having a unit electrode tab, and wherein the electrode assembly has a main body portion and a tab portion, the tab portion including a plurality of the unit electrode tabs protruding from the main body portion, the method comprising: collecting the plurality of unit electrode tabs by a tab guide; and welding the collected plurality of unit electrode tabs by vibration welding, wherein, during the vibration welding, the collected unit electrode tabs are held and pressed by a tab fixing block, such that vibration force applied to the unit electrode tabs is not transmitted to the main body portion of the electrode assembly.
The method of claim 8, wherein the tab fixing block includes two separate pieces, and during the vibration welding, the unit electrode tabs are held and pressed by the two pieces, being positioned in an interval therebetween.
The method of claim 8 or 9, wherein the tab guide includes two separate parts, and the plurality of unit electrode tabs are collected by being interposed between and guided by the two separate parts.
The method of any one of claims 8 to 10, wherein the vibration welding is performed by a relative movement between two separate portions of a welding part in a state the collected unit electrode tabs are interposed between the two portions.
The method of any one of claims 8 to 11, wherein during the vibration welding, the main body portion of the electrode assembly is placed on a plate and held in place by being pressed by a pusher.

Description

TECHNICAL FIELD The present invention relates to a system and a method for manufacturing an electrode assembly. More particularly, the present invention relates to a system for manufacturing an electrode assembly capable of preventing an electrode tab of the electrode assembly from being damaged during a welding process of the electrode tab. The present invention also relates to a method for manufacturing an electrode assembly, according to which an electrode tab of the electrode assembly can be prevented from damages resulting from a vibration force applied during the welding process of the electrode tab. BACKGROUND Secondary batteries, or often called rechargeable batteries, can be discharged by being used and then restored to their original state by charging. Secondary batteries have recently been widely used as an energy source of wireless devices, such as a personal digital devices, mobile telephone, or notebook computer. Moreover, the secondary battery has attracted attention as an energy source of an electric vehicle, a hybrid electric vehicle, and the like, which are regarded as a solution to the air pollution problem caused by traditional gasoline or diesel vehicles using fossil fuel. Due to the apparent advantages of the secondary battery over other traditional energy sources, the application of secondary battery continuously becomes wider and the consumer's demands for the secondary battery is also increasing. Among various secondary batteries, a lithium secondary battery is particularly widely used as an energy source for various electronic products because the lithium secondary battery shows a high energy density, a high operating voltage, as well as excellent storage and lifetime characteristics. In the meantime, secondary batteries can be also classified depending on the shape of a battery case. For example, they may be classified into cylindrical or prismatic batteries, according to which an electrode assembly is embedded in a cylindrical or prismatic metal can. Furthermore, in case of pouch-type batteries, the electrode assembly is embedded in a pouch-type case of an aluminum laminate sheet. The electrode assembly, embedded in the battery case, functions as a power generating element capable of charging and discharging. The electrode assembly comprises a positive electrode, a negative electrode, and a separator interposed between the positive and the negative electrodes. The electrode assembly can be generally classified into a jelly-roll type and a stack type. In case of the j elly-roll type electrode assembly, a positive electrode and a negative electrode, which are long sheet-shaped and are coated with an active material, are wound along their longitudinal direction, having a separator interposed therebetween. On the other hand, in case of the stack type electrode assembly, a plurality of positive electrodes and negative electrodes of a predetermined size are sequentially stacked on top of the other, having a separator interposed therebetween. At a longitudinal end of the stack type electrode assembly, a plurality of unit electrode tabs are provided. The unit electrode tabs are to be welded together and, depending on the specification of the electrode assembly, may be subsequently attached to an electrode lead for an electric connection to an external battery terminal. Otherwise, the bundled and welded unit electrode tabs, forming an electrode tab of the electrode assembly, may be directly connected to an external battery terminal. Anyway, in the process of forming an electrode tab by welding the bundled unit electrode tabs (typically called "pre-welding"), a defect can occur due to various reasons, particularly including occurrence of damages to the unit electrode tabs. Accordingly, it would be advantageous to develop a technology capable of addressing the above technical problem, by reducing or preventing damages to an electrode tab during the pre-welding process. SUMMARY OF THE INVENTION It is an objective of the present invention to provide a system and a method for manufacturing an electrode assembly. The problem is at least partially solved or alleviated by the subject-matter of independent claims, wherein further examples are incorporated in dependent claims. One aspect of the present invention relates to a system for manufacturing an electrode assembly. The electrode assembly may include a plurality of unit electrode cells stacked on one another. Each of the plurality of unit electrode cells may have a unit electrode tab. The electrode assembly may have a main body portion and a tab portion. The tab portion may include a plurality of the electrode tabs protruding from the main body portion. The system comprises a welding part configured to weld the plurality of unit electrode tabs by applying vibration force. The system may further comprise a tab guide for collecting the plurality of unit electrode tabs to supply the collected unit electrode tabs to the welding part for welding.