Cell & Pack Manufacturing

Architecture, Process, & Performance. A Comparative Framework - Prismatic Wound, ZStacked 1 OF 2 Wound cells are constructed by feeding a continuous web of anode, cathode & 2 separator layers into a rotating mandrel under tension and singulated at the end of each cell jelly roll production. Winding is typically a cheaper manufacturing approach with faster equipment, fewer operators, less cutting tool maintenance, etc. Stacked cells are assembled using singulated anode and cathode sheets woven into a Z shaped oscillating separator web, followed by a heat pressing operation to maintain the layer alignment.

Applications like Consumer Electronics & Premium EVs with high power & high energy requirements would benefit from Stacking architectures and are typically paired with high Ni / Co chemistries. Applications like Stationary storage & low cost EVs with would benefit from the cost and scalability advantages of winding, especially with large ESSʼs multiple paddle-wound jelly rolls connected in parallel. This can allow winding to maintain market share even as stacking catches up.

Source: sciencedirect, medium, xiaoweitop, tobmachine

CELL DESIGN ARCHITECTURE Sizing & Aspect Ratio

Stacked cells offer high flexibility in XY dimensions compared to Wound, but are limited in Z thickness (/JR) due to alignment risks as layer count increases

Component Selection

Electrode Foil Thickness: Since wound cells are assembled under web tension to maintain AC overhang, foils need to be thicker compared to stacked cells to prevent web breaking. Separator: Stacked cells require laminatable separators to maintain electrode alignment during assembly and early cell life. Laminated separator increases complexity in electrolyte migration within the cell.

Performance

Wound cells do not completely fill the available volume in prismatic cells and result in lower energy density. Wound cells have a lower tabs to layers ratio due to tab alignment challenges in winding resulting in higher impedance and increased DCFC time.

Safety & Durability

Wound structure of the electrode causes compressive and tensile loading on the electrode during cycling expansion. This can result in accelerated aging of the cell from wrinkle formation and make these cells prone to core collapse during impact loading around the corners if they lack adequate design considerations. Anode silicon content can affect the swelling rate and stresses.

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