MRI-like technique to detect what ails batteries

An MRI-based technique that can quickly diagnose what ails certain types of batteries – from determining how much charge remains, to detecting internal defects – without opening them up, has been developed by a team from New York University.

"The use of alternative energy and electrically powered vehicles will further increase the demand for better and safer batteries," observes Professor Alexej Jerschow, who led the research team. "However, there are currently only a limited set of tools available to diagnose a battery's health without destroying the battery. Our non-invasive technique offers a faster and more expansive method for making these assessments."

The researchers took inspiration from the MRI scan, which can produce images of the human body's organs in a non-invasive manner. They adopted a similar procedure where they measured tiny magnetic field changes surrounding the battery's electrochemical cells.

In their experiments, they examined Li-ion batteries in different states – various levels of charge and conditions (i.e. some damaged and others not). With these cells, the team say they were able to match magnetic field changes surrounding the batteries to different internal conditions, revealing state of charge and certain defects. These included bent and missing electrodes, as well as small foreign objects in the cell, which are flaws that can occur during the normal manufacturing process.

"With future enhancements to this method, it could provide a powerful means of predicting battery failures and battery lifetimes as well as facilitate the development of next-generation high-performance, high-capacity, and long-lasting or fast-charging batteries," concludes Prof. Jerschow.