A positive active material for rechargeable lithium batteries includes an active material component processed from a manganese-based compound. The transition metal compound is selected from Li_xMnO₂, Li_xMnF₂, Li_xMnS₂, Li_xMnO_2-zF_z, Li_xMnO_2-zS_z, Li_xMn_1-yM_yO₂, Li_xMn_1-yM_yF₂, Li_xMn_1-yM_yS₂, Li_xMn_1-yM_yO_2-zF_z, Li_xMn_1-yM_yO_2-zS_z, Li_xMn₂O₄, Li_xMn₂F₄, Li_xMn₂O_4-zF_z, Li_xMn₂O_4-zS_z, Li_xMn_2-yM_yO₄, Li_xMn_2-yM_yF₄, Li_xMn_2-yM_yS₄, Li_xMn_2-yM_yO_4-zF_z, or Li_xMn_2-yM_yO_4-zS_z where 0x1.5, 0.05y0.3, z1.0 and M is selected from Al, Co, Cr, Mg, Fe or La. A metallic oxide is coated on the active material component.