NDT for Monitoring and Inspection

The rapid growth of electric vehicles (EVs) and energy storage systems has made the reliable inspection of lithium-ion battery cells and power electronics essential, since undetected internal defects such as delamination, gas pockets, and lithium plating are a leading cause of thermal runaway yet remain inaccessible via conventional external measurements in these sealed, electrochemically active systems. Nondestructive testing (NDT)—particularly ultrasonic interrogation and acoustic signal analysis—has emerged as the primary inspection modality. Acoustic waves can penetrate sealed cell housings and return spatially resolved information about internal structure. The field is progressing from laboratory diagnostic tools toward fully automated, in-line manufacturing inspection systems, with growing integration of AI and machine learning–based defect classification expected to accelerate the transition toward zero-defect manufacturing and enhanced in-service monitoring. Here are three patents reflecting this direction in NDT for battery cells and EV power electronics.

US12368193B2

Acoustic Signal Based Analysis of Batteries

(Barry J. Van Tassell, Andrew G. Hsieh, Andrew M. Raphael, Shan Dou, and Shaurjo Biswas)

This patent presents a comprehensive acoustic signal–based inspection and diagnostics framework for lithium-ion battery cells. The system employs electrochemical-acoustic signal interrogation techniques, in which ultrasonic pulses are transmitted through a sealed battery cell. The resulting transmitted waveforms and reflections are analyzed with respect to acoustic time of flight (ToF), signal amplitude, and frequency content. The method can noninvasively determine multiple battery parameters, including state of charge, state of health, and manufacturing quality. Enabling single-point, noncontact measurement addresses one of the key limitations of conventional electrical testing, which cannot detect physical and structural defects inside sealed cells. This patent reflects the growing recognition that acoustic methods are among the most practically viable NDT tools for providing real-time, in-line quality control in battery manufacturing.

US2025/0266420A1

Tempo-Spatial Manipulation of Ultrasonics for a Solid-State Battery

(Qigui Wang, Liang Wang, Lei Chen, Xinxin Yao, and Yaohong Xiao)

This patent presents an advanced ultrasonic framework designed for the inspection and characterization of solid-state batteries. Compared to conventional liquid-electrolyte lithium-ion cells, solid-state batteries present additional NDT challenges: their ceramic/polymer solid electrolytes and tightly compressed electrode-electrolyte interfaces are subject to unique failure modes, including interfacial delamination, void formation at the lithium-electrolyte interface, and lithium dendrite penetration through the solid electrolyte layer. The approach adapts the timing, frequency, and spatial pattern of ultrasonic energy delivery to interrogate specific internal features of the solid-state cell. This patent extends acoustic NDT capability to next-generation battery chemistries, demonstrating the effectiveness of ultrasonic inspection methods in ensuring the safety and performance of solid-state EV batteries.

US12553866B2

Systems for Performing Acoustic Measurement of Batteries

(Yu Jason Yue, Biswas Shaurjo, Fong Yu Shi, Yu Dennis, Hsieh Andrew, D'orazio Ashlyn Leona, and Dulaney Austin Ryan)

This patent presents a dedicated hardware/software system for performing full-surface acoustic scanning of battery cells during manufacturing. The system employs pairs of ultrasonic transducers (transmitter/receiver) mounted on actuated motion stages that systematically scan the cell surface to develop a spatially resolved acoustic map of the entire cell. At each measurement location, acoustic waveforms are recorded and processed to extract metrics such as ToF, amplitude, and frequency-domain features, generating a two-dimensional acoustic image of the cell interior. The system is explicitly designed for in-line integration on a battery manufacturing production floor and is capable of identifying a wide range of defects critical to battery safety and performance, including electrode misalignment, delamination, voids, metallic contamination, and debonding between the electrode coating and the current collector. This patent demonstrates how acoustic NDT can transition from a laboratory research tool into an industrial-scale automated quality inspection system.

Patents Editor: Samir Mustapha, PhD, American University of Beirut, Beirut, Lebanon; sm154@aub.edu.lb