EPR Imaging of Metallic Lithium

We present a sensitive characterization method to image the microstructure of lithium deposits in lithium-ion battery components by Conduction Electron Paramagnetic Resonance Imaging (CEPRI). The versatility of the method is demonstrated for both, imaging surface-patterns of thick lithium metal anodes, as well as obtaining high-resolution images of lithium dendrites formed inside a separator with several micrometre pixel size. The determined spatial distribution of dendrites may then serve as an indicator of the current density distribution and, therefore, yields most valuable information for battery cell design. Accordingly, this method shows its capabilities in a research area where electron paramagnetic resonance imaging (EPRI) has not been utilized so far.