Key Takeaways
EV battery traceability is essential for:
- Tracking origins, materials, and production history for compliance and quality.
- Tracking and traceability information is communicated using barcodes and characters, either printed on labels or direct part marks (DPMs)
- The ability to read those characters and codes affects supply chain visibility and the effectiveness of tracking and tracing operations.
- Decoding challenging DPMs on reflective, irregular surfaces.
The growing importance of EV battery traceability in an increasingly complex regulatory landscape
EV battery manufacturing is a compartmentalized industry. Battery producers often produce a specific size and shape of a cell, such as prismatic, cylindrical, or pouch, then ship the cells to an automaker that assembles cells into modules and packs.
During production, automakers and EV battery manufacturers must quickly verify battery dimensions, material composition, performance, and other attributes to produce safe, compliant, high-quality batteries. As manufacturing techniques evolve and more battery producers enter the growing industry, identifying and verifying a component’s origin, composition, and production history will become increasingly important.
What's the difference between traceability and tracking in EV battery production?
Traceability gathers information about the manufacturing process, like where a product originated, what materials it contains, and how it was manufactured. Tracking collects and monitors data related to item movement, storage, and shipment.
Manufacturers often record and store this data electronically to comply with governmental regulations and international requirements, such as Internal Organization for Standardization (ISO) standards.
EV battery manufacturing traceability and tracking can record information throughout every step of the process, including:
- Raw material origins
- Potential hazardous materials
- Manufacturing history
- Service life
The scope of what data to track and its accessibility depends on industry and governmental regulations.
How do EV battery track and trace systems work?
Barcodes and barcode readers are the foundation of EV battery traceability and tracking. Users define an item using barcode generation software, including its name, origin, and material composition. Then, the software generates a code that gets applied to a battery or a component. Each time that code is scanned, it displays the definition created in the inventory management system. Users can update database information to denote changes, like when an EV battery moves onto the next manufacturing phase.
Since label-based barcodes can fall off and degrade, manufacturers typically imprint codes called direct part marks (DPMs) onto EV battery parts. While various marking methods and types of codes exist, two-dimensional (2D) QR and Data Matrix codes are the most common in the EV industry. Only image-based barcode readers can read and decode DPMs.
Why are EV battery tracing and tracking important?
Identifying issues and mitigating risk
Quickly recognizing and diagnosing production issues can minimize costs by preventing problems from spreading and affecting multiple manufacturing lines. The faster a manufacturer can trace a manufacturing issue to its source, the faster they can correct it.
Tracking and tracking to catch manufacturing issues is particularly useful in electrode manufacturing, one of the first steps of manufacturing a lithium-ion EV battery. The most common form of electrode coating, “wet coating,” entails mixing carbon, graphite, a binding agent, and other elements, and pouring the mixture onto anodes and cathodes. Defects like bubbles, holes, or crookedness in the coating can be one of the leading causes of short circuits and fires.
In case of a battery failure or manufacturing issue, component traceability, such as identifying what materials are in the electrode coating and where it was produced, is critical to mitigating costs. Automakers are also asking for greater electrode traceability from battery manufacturers so they can identify the root cause more quickly.
Imprinting DPMs on electrode-coated anodes and cathodes to trace manufacturing details and track usage is gaining traction. However, reading those DPMs comes with multiple challenges. First, electrode coatings are highly reflective, and their metal substrates are thin, complicating image formation. Second, electrode coating lines often move at high speeds— about 1.5 meters per second —so a barcode reader has to read 10 to 15 codes per second to keep up.
Cognex image-based barcode readers have a wide field of view (FoV), allowing them to capture multiple codes in one image. Advanced image formation technology like high-dynamic range (HDR) and HDR+ maximize image contrast and enable readers to recognize codes against the reflective surfaces, increasing read rates and speed.
Ensuring compliance with a digital product passport
The EV industry is well-regulated; however, the size and scope of regulations vary between regions and non-governmental organizations like ISO.
With the surge of EV manufacturing, a concentrated effort to track and trace EV batteries throughout the supply chain is emerging in the European Union. The EU is set to adopt an EV battery traceability program, a “battery passport," in 2027.
A group of 11 companies, including automakers BMW and Audi, are leading the charge in the form of The Battery Pass Consortium. Additional partners include Mercedes-Benz, EV battery producers Northvolt, CATL, and LG Energy Solution, and GS1, which sets international standards for barcodes and other coding systems.
The organization aims to create a digital infrastructure for batteries: a digital product passport (DPP). The effort aligns with the EU’s new battery regulation and will bring transparency to battery lifecycles and introduce sustainable business models, according to the consortium. A study published by the Battery Pass project suggests a passport program will reduce procurement and processing costs while increasing recycling rates.
QR codes are the heart of the battery passport program, relaying information such as recycled material content, performance and durability requirements, and a “chain of custody” system to provide battery traceability.
All EV battery manufacturers operating in the EU must implement a battery passport program by February 1, 2027. The program is a pilot for DPPs in other industries, and other countries are expected to apply similar standards, increasing the need for robust, versatile barcode reading.
What are the challenges of EV battery tracking and traceability?
Reflective, irregular metal surfaces and damaged codes complicate image formation
While DPMs can withstand the harsh EV battery manufacturing environment, they can be more complicated to read than label-based codes. Since DPMs are imprinted into metal, finding the optimal image contrast is difficult; label-based codes are black and white, making them easier for barcode scanners to find and decode.
The complexities of EV battery manufacturing can exacerbate these problems. Batteries can have stains, oil, or scratches that obstruct the code. Pouch-style batteries are thin and flexible, so the barcode scanner must have robust technology to account for wrinkles and irregular surfaces that complicate image recognition. Similarly, cylindrical batteries have curved, shiny surfaces that can distort the code and reflect too much light back at the scanner.
Cognex image-based barcode scanners use advanced image formation and code-reading technology to maximize image contrast, optimizing DPM decoding – even codes in low-contrast settings and damaged symbologies – for improved traceability. 2DMax with PowerGrid uses a shape-based algorithm to identify well-marked codes. At the same time, a texture-based tool locates damaged codes by analyzing patterns on the cell surface.
Maintaining fast line speeds
Battery producers are striving to increase throughput to keep up with demand from automakers, and every second counts. For example, in a cylindrical EV battery production, line speeds can exceed 240 parts per minute.
One challenge of throughput like that is quickly tracking and tracing EV batteries while limiting the number of "no-reads:" unsuccessful attempts to read a barcode. Increasing line speeds too much could result in more no-reads and less effective tracking and tracing, while slowing speeds to let a reader keep up would decrease throughput.
Cognex image-based barcode scanners facilitate high-speed operations like EV battery production while maintaining high read rates. HDR+ creates a uniform image in a single acquisition, simultaneously reducing exposure time and optimizing contrast, enabling faster line speeds.
Intermittent code placement
Components like EV battery modules and packs can have a variety of label-based and DPMs. Efficient EV battery tracking, and traceability must capture codes throughout the module and pack assembly processes, from printed circuit boards (PCBs) to fastening the top shell to the battery pack.
While capturing codes on different modules and packs is important, automation integrators, machine builders, and original equipment manufacturers (OEMs) must ensure their solutions are flexible and cost-effective. Adaptable barcode reading solutions are critical to minimizing changeover times when changing specifications, vendors, materials, or other manufacturing variables.
Finding the right lens, field of view, and depth of field are critical first steps to finding the optimal barcode solution. High-speed liquid lens technology allows the lens to bend and adapt to find the best field of view without using mechanical parts. The technology reduces the number of barcode scanners needed for large field-of-view or depth-of-field applications – like reading numerous codes on an EV battery pack or module – while boosting throughput.
To maximize read rates, it’s important to identify when, where, and why no-reads happen. Cognex developed the Edge Intelligence platform to provide real-time barcode reading analysis. Edge Intelligence can identify changes in label positioning, discover why a no-read occurred, chart code quality, and update multiple readers simultaneously. This information can help uncover the root cause of no-reads, enabling parties throughout the supply chain to maximize EV battery tracking and traceability.
The growing role and increasing significance of EV battery traceability
Tracking and tracing EV battery details like their production history, materials, chemistry, and percentage of recycled materials is critical to efficient manufacturing. Robust tracking and tracing systems isolate production issues and let EV battery manufacturers take corrective actions quickly to prevent rework and minimize costs. As the industry continues to grow and new standards are adopted, there will be a greater need for traceability throughout EV battery manufacturing. Traceability and tracking are critical to complying with industry regulations, mitigating risk, and optimizing production processes.
Quickly locating and decoding barcodes is the foundation of EV battery tracking and tracing systems. Direct part marks, or DPMs, are the most common form of codes in the industry, although some components, such as EV battery modules and packs, also use label-based codes. Reading barcodes on EV battery components is inherently difficult; optimizing read rates requires maximizing image contrast and being able to read codes on specular, nonlinear surfaces. Cognex image-based barcode scanners use advanced image formation and decoding technology that help EV battery manufacturers increase tracking and traceability by reading codes in challenging conditions without slowing down throughput.