How Ultrasound Technology is Addressing The Billion-Dollar Battery Reliability Problem
July 12, 2022

Battery reliability is a billion-dollar problem that will only continue to grow as production scales. And scaling it is: automakers and battery manufacturers are expected to scale at unprecedented rates and costs in the coming years. 

While the clock ticks toward our e-mobility future, we need to improve battery quality and production speed. But in order to do that, we need to make a change to business as usual.

Rethinking Battery Inspection: Overcoming the Limitations of Existing Electrical Methods

Current electrical methods of battery inspection are not sensitive to internal defects. Being blind to what’s going on inside each battery means achieving consistent quality is a guessing game.

On the other hand, when batteries are inspected using ultrasound technology, we can close the information gap typically experienced using standard electrical methods alone.

That’s why, in a time when battery production is rapidly ramping up, the ultrasound technology within Liminal’s EchoStat® solution improves battery safety, performance, and reliability.

Using a combination of ultrasonic transducers, well-defined acoustic pulses and sophisticated signal processing and pattern recognition algorithms, EchoStat delivers insightful, actionable data, such as electrolyte saturation quality and accurate predictions of downstream cell performance.

What use is this information to battery manufacturers? For one thing, measuring electrolyte saturation quality is a key advantage to not only ensuring battery safety and performance quality, but also ramping up to full production more efficiently.

Using machine learning, EchoStat develops a baseline model of the customers’ soaking process, which allows us to determine when the cells are fully saturated. One Liminal customer was able to reduce soaking time by 50% upon seeing their results.

Leveraging Ultrasound for In-Line Quality Inspection

Another way Liminal’s ultrasound technology improves battery production is by allowing for in-line quality inspection. EchoStat measurements can find outlier cells just a few hours into the soaking process, representing a 95% earlier in process detection of cell defects or soaking errors.

This quicker time-to-insight gives manufacturers visibility into their cell quality at a much earlier stage of the manufacturing process. 

The more we increase efficiency when building quality batteries, the more batteries we can make in a year, accelerating our EV future. This process acceleration provides an estimated savings of $3.5M per year per 1GWh line, by avoiding incremental costs on cells destined for scrap and achieving faster process optimization.

With typical electrical methods of inspection, battery makers & EV OEMs are blind to small manufacturing defects such as separator folds and holes, electrode misalignment, electrode folds, and foreign object debris. These issues can result in field failures such as the fires and explosions of Samsung Note 7 tablets in 2018, and the GM Chevy Bolt in 2020.

Liminal: Enhancing EV Battery Reliability, Safety, and Performance

Liminal now has under development advanced inspection techniques that will give visibility into micro-defects like separator folds and holes that cannot be found with current methods. EchoStat can also detect other defects such as electrode folds and misalignment, as well as metal object debris.

If you’re interested in improving battery cell quality and manufacturing processes, join us! Liminal is actively pursuing inspection opportunities during cell finishing (electrolyte soak, formation, aging) during process development, and in-line production—and we’re actively hiring. Connect with us.