Application of In Situ Techniques for Investigations in Lithium-Ion Battery Materials

Abstract

Some examples for the application of various in situ techniques in the investigation of lithium-ion battery materials are given. The effect of crystallite size on lithium insertion behavior of anatase TiO2 is shown by in situ Raman microscopy. In TiO2 with a crystallite size of 10-20 nm, an extended solid solution domain is found compared to samples with ca. 80 nm crystallite size. Graphite exfoliation is investigated by in situ Raman mapping and differential electrochemical mass spectrometry (DEMS). Inhomogeneities within single graphite particles are found with Raman mapping. CO2 formation at Li(Ni,Co,Al)O2 electrodes is monitored with DEMS and in situ ATR-SNIFTIRS. CO2 evolution is measured at elevated temperatures by DEMS, but formation of CO2, dissolved in the electrolyte, is also detected at room temperature by ATR-SNIFTIRS.