Background: Our customer required a compact coding method for narrow pouch cell tabs to enable full cell traceability. The available tab width created a demanding marking challenge because the identifier needed to be small enough to fit the tab geometry while remaining machine-readable on reflective metallic substrates. ARC therefore assessed whether Data Matrix codes could provide a more practical route than conventional QR codes for encoding short batch or cell identifiers on cathode and anode tab materials.
Challenge: The technical challenge was to print a high-resolution, machine-readable code on small metallic tabs without compromising the function of the component. ARC needed to demonstrate that printed codes could maintain contrast and dimensional consistency across Cr-treated aluminium cathode tabs and nickel-plated copper anode tabs. Key risks included limited marking area, variation in ink wetting between metal surfaces, module edge definition, aliasing, bleeding and the ability to scan reliably from a practical working distance.
Solution: ARC worked with its preferred printing partner to produce and assess prototype two-dimensional codes on representative tab materials. The trial focused on compact 12 x 12 Data Matrix codes measuring approximately 3 mm square, selected because they can encode short alphanumeric identifiers in a smaller footprint than typical QR codes. Printed samples were assessed for scan performance, code clarity, contrast against the metal finish, data capacity and microscopic print quality.
- Material Selection: Prototype codes were printed on both cathode and anode tabs to check whether the method was transferable across the two relevant tab substrates.
- Code Design: The trial used 12 x 12 Data Matrix codes capable of holding eight alphanumeric characters, providing sufficient capacity for short identifiers such as batch-style codes while keeping the printed mark within the narrow tab geometry.
- Scanning Assessment: prototype codes were scanned successfully using a mobile barcode application. The codes returned the expected eight-character alphanumeric text and could be scanned from approximately 30 cm above the tabs when the application zoom function was used.
- Microscopic Inspection: Inspection at 50× magnification confirmed good overall size consistency across both metal types, but also identified small aliasing and ink-bleeding effects. These features were attributed to the limited print area, achievable print resolution and differences in ink wetting on metallic surfaces compared with paper.
Results: The trial demonstrated that compact Data Matrix identifiers can be printed and read on narrow pouch cell tabs, supporting the feasibility of cell-level traceability on both cathode and anode tab materials. However, the work should be presented as a feasibility demonstration rather than a fully validated production process.
- Successful compact coding: The 3 mm square, 12 x 12 Data Matrix format provided adequate data capacity for eight-character alphanumeric identifiers and fitted the narrow tab format required by the project.
- Verified prototype readability: All seven complete prototype codes scanned correctly and returned the intended identifier, demonstrating functional readability on both Cr-treated aluminium and nickel-plated copper tab surfaces.
- Production-relevant limitations identified: Although aliasing and ink bleeding did not prevent scanning in the prototype trial, they remain important scale-up considerations because print quality, module edge definition and contrast variation will affect verification grade, read-rate robustness and process capability in production.
Conclusion: ARC demonstrated that Data Matrix code printing is a technically credible route for applying compact cell-level identifiers to narrow pouch cell tabs. The work confirmed that eight-character alphanumeric codes could be printed at approximately 3 mm square and scanned successfully on both cathode and anode tab substrates. The next development stage should define formal acceptance criteria, including verification grade, minimum read rate, process capability, durability after handling, and any impact on welding, electrical resistance or pouch-seal compatibility.