Battery Deformation Measurement Based on Electronic Speckle Pattern Interferometry

To accurately measure the full-field deformation of soft-packed lithium-ion batteries and improve the safety of battery industrial production, an electronic speckle pattern interferometry (ESPI) system was established. After irradiating the object with a laser, uniform speckle patterns were formed on the camera target plane. Quantitative measurement of battery deformation was conducted via charging and discharging experiments on lithium iron phosphate (LFP) lithium-ion batteries. Through the automatic control of the reference surface phase shifting device and the industrial camera, four-step phase shifting was completed, and the wrapped phase was acquired. A phase unwrapping algorithm combining temporal and spatial domains was proposed to obtain the absolute phase variation, thereby achieving battery deformation measurement. The results show that the system exhibits excellent deformation measurement capability.