Room temperature synthesis of Li-doped MnO2 and its electrochemical activity

A new method was developed to synthesize a uniform round-shaped Li-doped MnO₂ by ozonation of acidic MnSO₄ in the presence of Li⁺ ions. X-ray diffraction study showed that the prepared compound was of a hexagonal-closed-packed (hcp) crystal structure with an average crystallite size of ~ 103 nm. The merging of 221/240 and 061/002 lines suggested a high microtwinning defect. Chemical composition has been explained in terms of Ruetschi's cation vacancy model. The electrochemical properties were studied by recording discharge profile in 9 M KOH at 1 mA/0.1 g and 100 Ω/0.5 g. The discharge proceeded with homogenous solid-state reduction into MnOOH followed by subsequent formation of Mn(OH)₂ via dissolution-precipitation mechanism.