Lithium-substituted cobalt oxide spinels Li_xM_1-xCo₂O₄(M = Co²⁺, Zn²⁺; 0 ≤ x ≤ 0.4)

Abstract

Substitution of Li⁺ into Co₃O₄ and ZnCo₂O₄ gives rise to the solid solution series Li_xM_1-xCo₂O₄ (M = Co²⁺ or Zn²⁺) having the spinel structure upto x = 0.4. X-Ray diffraction intensities show that the spinel solid solutions are likely to have the following cation distributions: (Co²⁺)_t[Li⁺_xCo³⁺_2-3xCo⁴⁺_2x]₀O₄ and (Zn²⁺_1-xCo²⁺_x)_t[Li⁺_xCo³⁺_2-3xCo⁴⁺_2x] ₀O₄. Electrical resistivity and Seebeck coefficient data indicate that the electron transport in these systems occurs by a small-polaron hopping mechanism.