Jelly Roll (JR) Handling Defects in Li-ion Pouch Cell Manufacturing In lithium-ion pouch cell production, the Jelly Roll (JR) forms the core electrochemical structure of the battery. It consists of precisely arranged layers of anode, separator, and cathode. After winding, the jelly roll must be carefully transferred, pressed, inspected, and inserted into the aluminum laminate pouch. The handling stage is highly sensitive because electrodes and separators can be damaged by excessive mechanical force or contamination. Key Jelly Roll Handling Defects 1. JR Misalignment Misalignment occurs when the jelly roll is not correctly centered relative to the pouch cavity or sealing region. This can lead to uneven sealing pressure and dimensional deviations. 2. JR Tilt Insertion During loading, the jelly roll may enter the pouch at an angle instead of maintaining the intended orientation. This can create uneven pressure distribution and affect sealing quality. 3. JR Forward / Backward Posit...

Common Laminate & Pocket Defects in Li-ion Pouch Cell Manufacturing In lithium-ion pouch cell manufacturing, the quality of the aluminum laminate film and pocket formation plays a critical role in the overall safety, reliability, and performance of the battery cell. Before the jelly roll is inserted and sealing begins, the laminate goes through several precise operations such as roll loading, cavity punching, pocket cutting, folding, and alignment inspection. Any defect generated during these early stages can propagate further down the production line and eventually lead to cell failure, leakage, swelling, or safety-related issues. Understanding these defects is therefore essential for maintaining stable processes and consistent cell quality. 1. Laminate Scratch Surface scratches on the aluminum laminate film can weaken the barrier layer. Depending on their severity and location, they may increase the risk of moisture ingress or electrolyte leakage over time. 2. Laminate Wri...

Final Inspection & Dispatch in Lithium-Ion Pouch Cell Manufacturing Final Inspection and Dispatch is the last stage in lithium-ion pouch cell manufacturing. After Final Quality Inspection, this stage confirms that only fully verified cells are released for customers or battery-module assembly. Purpose of Final Inspection & Dispatch Perform final verification of cell quality Confirm correct packaging and labeling Maintain complete traceability Prepare cells for safe transportation Final Inspection Activities 1. Appearance Check Cells are visually checked for surface cleanliness, laminate condition, FEF quality, seal integrity, scratches, dents, and other physical damage. 2. Electrical Verification Final electrical checks may include an OCV re-check, internal-resistance confirmation, and verification of previous test results. This helps confirm that the cell remains stable after earlier inspection stages. 3. Barcode & Traceability Check Each cell is checked for c...

FQI (Final Quality Inspection) in Lithium-Ion Pouch Cell Manufacturing FQI is the final major quality-control gate before a lithium-ion pouch cell proceeds to final inspection, packaging, and dispatch. It combines visual, dimensional, electrical, and traceability checks to verify that the cell meets its defined requirements. Purpose of FQI Verify overall cell quality Detect defects that may have passed earlier stages Confirm compliance with specifications Prevent non-conforming cells from reaching customers Key Inspection Areas in FQI 1. Visual Inspection Cells are checked for surface scratches, laminate wrinkles, seal defects, contamination, corner damage, and other visible abnormalities. 2. Dimensional Inspection Critical dimensions are verified using CCD systems or gauges. Typical parameters include cell length and width, sealant height, tab distance, degassing-side dimensions, and corner geometry. 3. Electrical Testing OCV verification Internal resistance measurement H...

X-Ray Inspection in Lithium-Ion Pouch Cell Manufacturing X-ray inspection provides a non-destructive way to examine the internal structure of a lithium-ion pouch cell without opening it. It is used to identify internal conditions that may not be visible from the outside. Purpose of X-Ray Inspection Verify jelly roll or electrode-stack alignment Check tab positioning and connections Identify internal misalignment or damage Verify structural consistency between cells Typical Inspection Areas 1. Jelly Roll / Electrode Alignment X-ray images can reveal shifts, uneven alignment, or deformation within the internal electrode structure. 2. Tab Position Tab location and connection geometry can be checked to identify abnormal positioning that may affect downstream electrical or assembly performance. 3. Internal Damage Mechanical deformation, unusual internal geometry, or other abnormalities can be identified without opening the cell. 4. Foreign Particle Detection Dense foreign par...

OCV (Open Circuit Voltage) Testing in Lithium-Ion Pouch Cell Manufacturing After First Edge Folding, OCV testing is an important electrical evaluation of the lithium-ion pouch cell. It measures the cell voltage without applying an external load and helps identify abnormal electrical conditions. What is Open Circuit Voltage? Open Circuit Voltage is the voltage measured across the terminals of a battery when no external current is flowing. The measured value reflects the electrochemical state of the cell under the specified test conditions. Purpose of OCV Testing Verify the electrical condition of the cell Identify abnormal or unstable cells Support formation and aging quality checks Prevent abnormal cells from moving to later stages OCV Testing Process 1. Cell Positioning The cell is correctly positioned in the test fixture and the terminals are aligned with the measurement contacts. 2. Electrical Contact The positive and negative terminals are connected to the measurement sy...

FEF (First Edge Folding) in Lithium-Ion Pouch Cell Manufacturing After degassing, First Edge Folding (FEF) is used to fold the pouch edges in a controlled manner. The process improves mechanical robustness and helps protect the sensitive sealing region during downstream handling and assembly. Purpose of FEF Protect the sealing area from mechanical damage Improve pouch structural rigidity Reduce stress around the sealing region Prepare the cell for downstream handling Why Edge Folding is Required After degassing and resealing, pouch edges can remain relatively exposed. They may experience bending, impact, or stress concentration around the seal corners. Controlled folding helps reinforce these areas. FEF Process Sequence The cell is positioned in the folding station. Pouch edges are aligned precisely. Folding tools apply controlled force. The folded edges are pressed to maintain the required shape. The finished fold is inspected. Critical Process Parameters Folding pressure:...