Cost-efficient non-destructive characterization technique for the battery system

Title: Design of a low-cost ultrasonic testing instrument for battery metrology
Authors: Amsterdam, et al.,
Journal: Electrochimica Acta Link

Non-destructive characterization has become crucial for understanding the operation and extracting key performance metrics of commercial batteries. In this paper, the authors introduce the application of scanning acoustic microscopy using ultrasound for battery systems, which can offer high-end performance at minimal cost. The paper provides an overview of various geometries used in ultrasonic techniques depending on the mode of operation (i.e., transmission, pulse-echo, and pitch-catch), as well as the basic principles and mathematical equations used to derive physical properties from parameters extracted through ultrasound measurements, such as time of flight and amplitude.

Additionally, it offers insights into the hardware and software involved in ultrasound measurements, with specific information on different components and outlines potential caveats along with preventative guidelines for proper equipment operation. To demonstrate feasibility, the authors perform scanning acoustic microscopy on an assembled pouch cell with known electrode and electrolyte compositions to assess wettability and compatibility of the electrolyte with the electrodes.

As the technique is still in its early stage, standardization of the experimental setup and refinement of analysis protocols are likely to be followed. Furthermore, the spatial resolution—currently on the order of ~100 µm—may need to be improved to enable more reliable routine measurements, especially considering the typical dimension of cathodes and anodes in commercial cells, to compete effectively with X-ray computed tomography which is a well-established method in the battery industry.