Hydroxyl as a defect of the manganese dioxide lattice and its applications to the dry cell battery

Manganese dioxide polymorphs with different OH− contents were prepared under various reaction conditions. X-ray diffraction measurements showed the presence of orthorhombic, tetragonal and hexagonal forms of MnO2. Infrared absorption spectra in frequency range 200–4000 cm−1 of the different modifications were studied. The infrared absorption spectra showed the presence of hydroxyl groups in some forms of MnO2 and the lack of such groups in other forms. The discharge behaviour and electrochemical activity of the prepared samples was determined in an electrolyte containing NH4Cl and ZnCl2. An attempt was made to correlate the structural parameters and OH− content with the electrochemical activity of MnO2 in the light of the cation vacancy model.