Analysis of the surface of lithium in organic electrolyte by atomic force microscopy, Fourier transform infrared spectroscopy and scanning auger electron microscopy

The surface of lithium has been analyzed in a dry-air atmosphere and in 1 M LiClO4/PC by in situ AFM observation and FTIR spectroscopy. High-resolution AFM discloses the nano-structure of the lithium surface which consists of grain boundaries, many ridge-lines, and flat areas. After immersing lithium in LiClO4/PC, these lines swelled and large particles appeared. The surface chemistry of lithium has been examined by ex situ XPS and SAM. It is found that Li2CO3 and Li2O localize on the ridge-lines and the grain boundaries. The morphological change due to lithium deposition occurs as a formation of particles on the ridge-lines and the grain boundaries.