The Thermo Scientific™ LInspector™ Edge In-line Mass Profilometer from Thermo Fisher Scientific offers next-generation electrode loading analysis, helping the battery industry meet its ever-evolving performance and economic challenges.
This article discusses the LInspector Edge’s potential to revolutionize electrode coating process control and the benefits this will bring to the battery manufacturing industry.
Electrode Coating Challenges in Battery Manufacturing
The manufacture of cathodes and anodes involves applying a slurry of active materials to both sides of a metal substrate. This slurry flows from the slot die coater onto the moving substrate before being transported to a drying oven.
The web is flipped to repeat this process on the reverse side of the substrate, producing a coated, dried electrode roll which is compressed and slit down prior to proceeding to cell assembly.
Image Credit: Thermo Fisher Scientific – Production Process & Analytics
It can be especially difficult to maintain consistency during slurry mixing, potentially causing issues related to non-uniform energy density, inconsistent flow, blockages, and agglomeration in the electrode coating process.
These technical challenges are exacerbated by exacting electrode coating uniformity specifications, as well as the ongoing need to maximize line speeds in order to maximize production yield.
It is also important to note that electrode coating is one of the initial foundational steps in the battery manufacturing process. If this process is not completed optimally, it may adversely affect every downstream process and, ultimately, have a defining impact on overall process economics.
Currently, battery manufacturers face significant challenges with visual coating inspection, which detects only surface defects, or with conventional scanning analyzers that provide limited data. These scanners measure less than 5 % of the total electrode area and update only every 3 to 5 seconds, making them insufficient for comprehensive quality control.
Operators lack timely and comprehensive data to ensure the uniformity of the advancing product. As a result, defects are often detected much later—typically at the cell inspection stage—when the material has already undergone further processing. This delay leads to higher-value scrap, increasing both material waste and production costs.
Advantages of Mass Profilometry in Battery Manufacturing
Mass profilometry represents an exciting development because it fills a notable gap in battery manufacturers’ current analysis toolkit. Mass profilometry’s improved resolution, level of coverage, and complete traceability allow battery manufacturers to view new levels of detail at unprecedented speeds, identifying problems early and quickly.
It is now possible to achieve complete electrode coating analysis in real-time at full line speed, simply by installing the LInspector™ Edge immediately after the initial coating step, and/or after drying.
This approach allows operators to reliably detect issues as they arise, providing a secure basis for timely remedial action and ensuring that the electrode coating process runs well, minimizing waste and maximizing profits by preserving downstream manufacturing capacity.
The LInspector Edge also offers complete traceability, with the loading level of every square millimeter of electrode now attainable. This is key to enabling comprehensive and in-depth analysis of battery failures.
In-Depth Data Generation via Mass Profilometry
The LInspector Edge is able to measure every stripe and patch across the web once every millisecond at a measurement spot size of a square millimeter. This equates to one million data points per second on a 1-meter-wide web.
This level of insight represents a significant improvement over a conventional scanning gauge, which travels back and forth across the web every three to five seconds with a much larger measurement spot size. These measurement instruments are able to produce 200 to 300 data points per second at best.
Taking these figures into account, the LInspector™ Edge offers a 3000 to 5000-fold increase in the amount of data generated versus its conventional counterparts.
This increase in available data has the potential to drive significant advancements. It is widely recognized that process economics have yet to fully support commoditized battery production, while manufacturers also face increasingly stringent performance targets.
The LInspector Edge generates the extensive data needed to drive improvements in both efficiency and performance, helping to bridge these gaps in battery manufacturing.
Unparalleled Data Quality
The dramatic increase in the amount of data generated via the LInspector Edge includes at least a three- to ten-fold improvement in cross-web resolution versus current scanning systems, which themselves outperform visual inspection systems only able to detect surface defects.
This improved resolution is especially important at the edges, where improved resolution results in enhanced edge loading shape definition and increased sensitivity to critical coating edge transitional characteristics.
It is also important to note the impact of switching to a detector able to instantaneously measure across the full width. This capability results in comprehensive data with nothing missed.
Implications for Manual Process Control and Process Development
Manually operating an electrode coating line requires continuous adjustments to ensure products meet defined specifications. The longer the delay between taking action and observing its effect, the less effective the control. Additionally, a lack of clarity regarding the precise outcome of an adjustment further complicates process optimization.
The LInspector Edge allows operators to detect a problem almost immediately, allowing them to take remedial action and instantly assess its impact.
The instrument’s higher resolution allows it to detect less pronounced non-uniformities with a significant impact on product performance perspective.
Continuous and complete coverage reduces the chance of these historically imperceptible defects being missed, resulting in a more reliable assessment of the potential impact of corrective action.
These powerful features give operators a degree of manual control that is both more secure and more responsive, delivering more confident and consistent process operation over the long term.
In process development, the benefits extend even further as performance-linked specifications are still being refined. A key objective at this stage is to establish clear cause-and-effect relationships, identifying which process-related factors contribute to specific quality and performance outcomes.
The data provided by LInspector Edge makes it significantly easier to define specifications that reliably correlate with superior performance and to develop a process capable of consistently meeting them.
Whether in development or production, the bottom line is that mass profilometry enhances our ability to observe effects and accurately link them to their causes. In doing so, it directly supports the development of the knowledge base needed to effectively engineer and control the electrode coating process.
Image Credit: Thermo Fisher Scientific – Production Process & Analytics
Automated Control Options
The data stream from conventional scanning systems is not optimized for automated control. In a typical setup, the roll advances at speeds of 60–120 meters per minute while the scanner moves back and forth in a zigzag pattern.
However, this method does not provide a true cross-web profile, as each scan captures only a small portion of the roll—approximately 5–10 meters—during a single pass.
Additionally, variability in the machine direction can introduce inaccuracies in cross-direction measurements, requiring multiple scans to construct a precise cross-direction profile. This inefficiency limits the system’s ability to provide real-time, high-accuracy data for effective process control.
There is also the risk that the scanner only catches a corner of a patch or completely misses patches, effectively delivering data that is not statistically representative of the lot. This risk, coupled with a relatively slow measurement time and poor resolution results in closed-loop controls with limited responsiveness and sub-optimal outcomes.
The LInspector Edge successfully addresses these limitations, providing a vastly improved data stream that is ideally suited to use with automation. The instrument measures a true cross profile in close to real-time, providing measurement feedback for automated process adjustments in just milliseconds rather than tens of seconds.
Its capacity to rapidly provide high-quality information makes the LInspector Edge ideally suited to building effective control hierarchies with powerful automated control techniques for optimizing process operation.
Figure 1. Traversing single point sensors only measure 2% to 4% of the electrode material (note red trace of measurement spot). Image Credit: Thermo Fisher Scientific – Production Process & Analytics
Figure 2. Mass profilometry measurement. Image Credit: Thermo Fisher Scientific – Production Process & Analytics
The Future of Mass Profilometry and Electrode Coating Processes
The battery manufacturing industry is acutely aware of the inefficiencies it currently faces and the increasingly demanding targets for improvement around battery performance. It is anticipated that mass profilometry will become increasingly utilized throughout the sector, its speed and resolution driving its widespread adoption.
Mass profilometry is set to unlock a deeper and more comprehensive understanding of the coating process than is currently available. This will allow operators to manipulate process levers more effectively and achieve nuanced, automated control. These capabilities will drive the electrode coating process to never-before-seen levels of performance.
Summary
The LInspector Edge delivers on two key fronts when employed in the battery manufacturing sector. It enables operators to discern correlations between electrode coating uniformity and performance, and tiny defects and undesirable characteristics.
The LInspector Edge will also enable consistent production to increasingly demanding specifications. This is especially important to process economics, due to the potential for significant waste reduction and more optimized material usage allowed by detecting defects much earlier in the process flow. These capabilities ultimately improve throughput, resulting in a major positive impact on profitability.
This advanced technology supports the delivery of a number of key goals for battery manufacturers: improved safety, higher performance, greater consistency, and reduced production costs.
As the world continues its transition to electrically powered transport and a general reliance on electrical power, the ability to deliver better, more cost-efficient batteries will become increasingly key. The LInspector Edge is set to become a key part of this process.
Acknowledgments
Produced from materials originally authored by Chuck Blanchette from Thermo Scientific.
This information has been sourced, reviewed and adapted from materials provided by Thermo Fisher Scientific – Production Process & Analytics.
For more information on this source, please visit Thermo Fisher Scientific – Production Process & Analytics.