Raman Microscopy Applied to Rechargeable Lithium-Ion Cells-Steps towards in situ Raman Imaging with Increased Optical Efficiency

Important improvements have been made in an in situ Raman cell developed to monitor the processes of lithium intercalation into the carbon and metal oxide materials used in lithium-ion cells. By reducing the electrolyte gap in the cell and changing the optical arrangement, the signal-to-noise ratio could be improved by a factor of about 20. The optimized cell gives optical access to either electrode (anode or cathode) employed in commercial lithium-ion batteries. The optical efficiency is such that Raman maps of electrode surface segments can be recorded under in situ conditions with an acquisition time of about 30 s per spectrum.