Cell & Pack Manufacturing

Manufacturing Process Map - 2. Cell Assembly - Cylindrical Challenges

metal contamination; jelly roll fit

Minor Challenge missing or multiple insulators

2. TAB SHAPING & CANNING

The jelly roll is put in the cylindrical can and then fixed through welding (resistance or laser). High-speed mechanical deformation process (beading). SPEED: 300-600 parts/min

1. WINDING & TAB WELDING Winding the cathode, anode, and two separator rolls. Ultrasonic welding the aluminum and copper tabs onto the cathode and anode respectively. SPEED: 30 parts/min

Note on tabless cells

There is no tab welding step. Instead, there are folded (notched) aluminum or copper ends. SPEED: 30-60 parts/min (depending on jelly roll size)

3. INSULATOR PLACEMENT

Insulator is punched and placed onto cell opening.

4. TOP CAP WELDING

Top cap is laser welded onto cathode tab.

Challenge

false positives

Challenge

Challenges

weld spatter; weld quality

5. HI-POT INSPECTION Internal short check

6. ELECTROLYTE INJECTION + SEALED

speed of analysis doesn’t allow real-time analysis

Challenges

anode, cathode, separator alignment; tabing, taping, cutting accuracy; tab welding quality (can introduce safety issues)

7. PHYSICAL INSPECTION

Through CT and/or X-Ray, the battery cell is analyzed to detect potential defects.

of total manufacturing cost

scrap rate

Electrolyte is injected into the vacuumed can. The can is pressurized to accelerate electrolyte absorption and then crimped, final height sizing.

Challenges

electrolyte absorption due to density; pooling of electrolyte; scratching and contamination (during crimping)

Challenges

8. DEGASSING/ PRE-CHARGE

Optional process to remove gas

exhaust gas treatment (for open pre-charge); avoiding residual gas during sealing and folding steps

*Graphics courtesy of LG Energy Solution. Reproduced with permission. Source: LG Energy; BCG; RWTH PEM; internal expertise

Extracted from the PDF; charts and images may read imperfectly.