Distortion of MnO6 octahedra and electrochemical activity of Nstutite-based MnO2 polymorphs for alkaline electrolytes—an FTIR study

Infrared fourier transform (FTIR) spectroscopic analysis of four commercial manganese dioxides having applications in alkaline batteries is reported. These samples of different alkaline activity have Nstutite or γ-MnO2 as the major phase. With respect to the interaction of Mn with OH− and other groups, the development of weak bands around 1363 cm−1 represents the variation in discharge performance. Significant changes are seen in the MnO6 octahedral arrangement from sample to sample by examining the spectra in low-frequency regions. Distortion of MnO6 octahedra by the constituent water promotes the electrochemical behaviour. In general, the alkaline electrochemical activity of Nstutite MnO2 samples can be understood from their infrared spectra.