Characterization and Failure Analysis

Sandia tests batteries to failure to determine the safety design margins. Publicity of Sandia tests often is focused on the strong reactions that occur when lithium-ion batteries release energy under abuse conditions without consideration of the significant improvements that have been realized in recent years.

Our abuse testing provides a wealth of data about a battery pack’s/module’s performance under stressful conditions, but the testing data itself can only reveal so much about an energy storage system’s strengths and weaknesses.

Once testing is complete and a storage system’s attributes and limits are determined, our scientists and engineers work with the manufacturer’s personnel to characterize and analyze the materials we tested to determine failure mechanisms and to develop a comprehensive, science-based understanding of battery failure. The more we can learn from any system failure, the better our data can assist developers in designing and modeling the next generation of energy storage systems with improved performance, better safety, and higher reliability. Our characterization and failure-analysis capabilities include

A Sandia researcher analyzes the data from a recent battery abuse test.

• electrochemical characterization: complex impedance spectroscopy, conductivity, solution electrochemistry;
• battery separator evaluation platform: thermal and mechanical integrity;
• electron and optical microscopy;
• x-ray computed tomography: 1 ft³ scan area, 10 μm practical resolution; and
• destructive physical analysis.