Raman spectroscopy for investigating lithium deposition/dissolution and diffusion at the microelectrode surface.

We developed an Raman spectroscopy method to visualize lithium deposition and diffusion at the microelectrode interface. Lithium deposition released free EC and FSA, while dissolution promoted rapid Li coordination. The estimated diffusion layer thickness matched theoretical predictions, highlighting micro-Raman spectroscopy's potential for studying lithium-ion battery interfaces.