KR-20220081297-A - Lazer welding system of secondary battery

Abstract

The secondary battery laser welding system includes: an oscillator having a laser module for laser welding a tab and an electrode of a secondary battery, and a photodiode for measuring an output value of the laser module; an interface unit connected to the oscillator and replacing a digital value with an analog value; a first fish transmitting an output value; a first control unit receiving the output value transmitted from the first PC and transmitting the output value to the interface unit; a second fish that transmits the output value; a second control unit receiving the output value transmitted from the second PC and transmitting the output value to the interface unit; a first power monitoring unit receiving the gate signal to the interface unit and receiving the output value from the oscillator and transmitting the output value to the first PC; and a second power monitoring unit configured to receive the gate signal to the interface unit, receive the output value from the oscillator, and transmit the output value to the second PC.

Inventors

• JEONGMIN YANG
• HANKWON JUNG
• SEUNGJIN SHIN
• ILGEUN LEE

Assignees

• LG ELECTRONICS INC

Dates

Publication Date

20220615

Application Date

20211206

Priority Date

20201208

Claims (5)

1. an oscillator having a laser module for laser welding a tab and an electrode of a secondary battery, and a photodiode for measuring an output value of the laser module; an interface unit connected to the oscillator and replacing a digital value with an analog value; a first fish transmitting an output value; a first control unit receiving the output value transmitted from the first PC and transmitting the output value to the interface unit; a second fish that transmits the output value; a second control unit receiving the output value transmitted from the second PC and transmitting the output value to the interface unit; a first power monitoring unit receiving a gate signal to the interface unit and receiving an output value from the oscillator and transmitting the output value to the first PC; and and a second power monitoring unit receiving a gate signal to the interface unit and receiving an output value from the oscillator and transmitting the output value to the second PC.
2. The method of claim 1, The interface unit is a master interface for receiving the output value transmitted from the first control unit and receiving the output value transmitted from the second control unit; A secondary battery laser welding system including a slave interface for transmitting an output value with a time difference to the oscillator.
3. 3. The method of claim 2, The slave interface is a secondary battery laser welding system for transmitting the gate signal to the first power monitoring unit and the second power monitoring unit, respectively.
4. 4. The method of claim 3, The first monitoring unit calculates the output value of the laser module based on the gate signal, and transmits the calculated result data to the first PC, The second monitoring unit calculates the output value of the laser module based on the gate signal, and transmits the calculated result data to the secondary battery laser welding system.
5. 5. The method of claim 4, a scanner comprising a lens and adjusting the lens; The first fish transmits a first welding position data value, the first control unit receives a first welding position data value, and transmits a first welding position data value to the scanner; The second fish transmits a second welding position data value, The second control unit receives a second welding position data value, and transmits the second welding position data value to the scanner.

Description

Laser welding system of secondary battery The present invention relates to a secondary battery, and more particularly, to a laser welding system for a secondary battery for laser welding a tab and an electrode of the secondary battery. A secondary battery is a device that converts electrical energy into chemical energy, stores it, and generates electricity when needed. Both charging and discharging occur at one electrode, and the anode (Anode, -pole) and the cathode (Cathode, +pole) are distinguished based on the discharge response. A secondary battery includes a positive and negative electrode plate coated with an active material on a current collector, a separator separating the positive and negative plates, an electrolyte that transfers ions through the separator, a case accommodating the positive and negative plates, the separator and the negative electrode; and a lead tab connected to the negative electrode plate and drawn out. The secondary battery may be classified into a cylindrical type, a prismatic type, and a pouched type according to its shape. The pouch-type secondary battery is widely used in the secondary battery industry because its shape can be relatively free, including a case such as a flexible pouch, and the manufacturing process is relatively easy and the manufacturing cost is low. An example of the secondary battery is a pouch-type secondary battery incorporating a thermally expansible layer disclosed in Korean Patent Application Laid-Open No. 10-2018-0095982 A (published on August 29, 2018), and such a pouch-type secondary battery includes a positive electrode, a negative electrode, an electrode current collector including a separator; and a pouch surrounding the electrode current collector. Equipment for manufacturing a secondary battery may include a laser module (ie, a laser oscillator) capable of welding the positive electrode tab and the positive electrode of the electrode current collector and welding the negative electrode tab and the negative electrode of the electrode current collector. 1 is a view showing a secondary battery according to the present embodiment; 2 is a view showing a process of manufacturing a secondary battery according to the present embodiment; 3 is a block diagram illustrating a laser welding system for a secondary battery according to the present embodiment; 4 is a perspective view of the oscillator shown in FIG. 3; 5 is a diagram illustrating a laser output value over time during normal emission by the oscillator according to the present embodiment; 6 is a diagram in which laser spot welding is shown together during normal emission by the oscillator according to the present embodiment; 7 is a diagram showing laser output values over time when abnormal emission by the oscillator according to the present embodiment is performed; 8 is a diagram illustrating a laser welding spot when abnormal emission by the oscillator according to the present embodiment is performed. Hereinafter, specific embodiments of the present invention will be described in detail with drawings. 1 is a diagram illustrating a secondary battery according to this embodiment, and FIG. 2 is a diagram illustrating a process of manufacturing the secondary battery according to this embodiment. The secondary battery 1 may include a pouch 2 and a cell 3 surrounded by the pouch 2 , and the cell 3 may be protected by the pouch 2 . An example of the pouch 2 may include an aluminum pouch 2A and a bonding layer 2B (refer to FIG. 2 ) formed on one surface of the aluminum pouch 2A. The cell 3 may include an electrode plate assembly (or stacked cell) in which a plurality of electrode plates are stacked such that a separator (ie, a separator) is positioned between a pair of adjacent electrode plates, and such an electrode plate assembly As shown in (a) of FIG. 2 , a positive electrode tab 4 and a negative electrode tab 5 connected to different electrode plates may be provided. As shown in (b) of FIG. 2 by a laser welding system (refer to FIG. 3 ) in the cell 3 , the positive electrode 6 may be welded to the positive electrode tab 4 , and the positive electrode 6 may be welded to the negative electrode tab 5 by a laser welding system (see FIG. 3 ). The cathode electrode 7 may be welded. The pouch 2 may be introduced into the secondary battery packaging equipment (not shown) in a state wound on a pouch roll (not shown), and the pouch 2 is a unit pouch of a rectangular shape as shown in (c) of 2 can be cut with Hereinafter, the unit pouch will be referred to as the pouch 2 and will be described. In the cell 3, the positive electrode 6 is bonded to the positive electrode tab 4, and the negative electrode 7 is bonded to the negative electrode tab 5. As shown in FIG. 2(d), the pouch It can be placed on the bonding layer 2B of (2), and the pouch 2 can be folded to cover both sides of the cell 3, as shown in FIG. 2E. 3 is a block diagram illustrating a laser welding system for a secondary battery according to t