A sacrificial positive active material for a lithium-ion electrochemical element which is a compound of formula (Li.sub.2O).sub.x (MnO.sub.2).sub.y(MnO).sub.z(MO.sub.a).sub.t in which: x+y+z+t=1; 1−x−y≥0; 0.97≥x≥0.6; y≤0.45; x −0.17; y≥0; y+z>0; t≥0; 1≤a<3. M is selected from the group consisting of Fe, Co, Ni, B, Al, Ti, Si, V, Mo, Zr and a mixture thereof.

A compound of formula Li.sub.4+xMnM.sup.1.sub.aM.sup.2.sub.bO.sub.c wherein: M.sup.1 is selected from the group consisting in Ni, Mn, Co, Fe and a mixture thereof; M.sup.2 is selected from the group consisting in Si, Ti, Mo, B, Al and a mixture thereof;
with: −1.2≦x≦3; 0<a≦2.5; 0≦b≦1.5; 4.3≦c≦10; and c=4+a+n.Math.b+x/2
wherein n=2 when M.sup.2 is selected from the group consisting in Si, Ti, Mo or a mixture thereof; and n=1.5 when M.sup.2 is selected from the group consisting in B, Al or a mixture thereof; and n=0 if b=0.

Provided is a metal oxide containing a brownmillerite-type manganese oxide represented by (Ca.sub.2-xA.sub.x)(Mn.sub.yAl.sub.zE.sub.2-y-z).sub.wO.sub.5+δ (in the formula, A represents one or more alkaline earth metal elements other than Ca; E represents one or more 3d transition metal elements or earth metal elements other than Mn and Al; and x, y, z, δ, and w satisfy 0≤x≤2, 0<y≤2, 0≤z<2, 0<y+z≤2, 0≤δ≤0.5, and 0.8≤w≤1.2), wherein the metal oxide has a defect in a (020) plane of a crystal of the brownmillerite-type manganese oxide.

A positive electrode material for lithium secondary batteries capable of easily doping vanadium oxide with molybdenum, and a method of manufacturing the same are disclosed. The method of manufacturing a positive electrode material for lithium secondary batteries includes (a) reacting vanadium oxide with a water-soluble molybdenum-based compound in the presence of a solvent; and (b) thermally treating the reaction product of (a).

Cathode materials for lithium ion batteries, lithium ion batteries incorporating the cathode materials, and methods of operating the lithium ion batteries are provided. The materials are composed of lithium metal oxides that include two different metals.

A positive electrode material for lithium secondary batteries capable of easily doping vanadium oxide with molybdenum, and a method of manufacturing the same are disclosed. The method of manufacturing a positive electrode material for lithium secondary batteries includes (a) reacting vanadium oxide with a water-soluble molybdenum-based compound in the presence of a solvent; and (b) thermally treating the reaction product of (a).

A sacrificial positive active material for a lithium-ion electrochemical element which is a compound of formula (Li.sub.2O).sub.x (MnO.sub.2).sub.y(MnO).sub.z(MO.sub.a).sub.t in which: x+y+z+t=1; 1xy0; 0.97x0.6; y0.45; x 0.17; y0; y+z>0; t0; 1a<3. M is selected from the group consisting of Fe, Co, Ni, B, Al, Ti, Si, V, Mo, Zr and a mixture thereof.

A single-crystalline LnBM.sub.2O.sub.5+ or LnBM.sub.2O.sub.5.5+ compound is provided, which includes an ordered oxygen vacancy structure; wherein Ln is a lanthanide, B is an alkali earth metal, M is a transition metal, O is oxygen, and 01. Methods of making and using the compound, and devices and compositions including same are also provided.

A cathode active material contains a compound represented by composition formula (1): Li.sub.xNa.sub.y{Li.sub.Na.sub.Mn.sub.(1z)A.sub.z}O.sub.2. In the formula, A represents at least one selected from the group consisting of Co, Ni, Fe, and Al, and the following conditions are met: 0.75x1.0, 0<y0.01, 0.75<x+y1, 0.160.3, 0<0.01, 0.2+0.3, and 0z0.15.

Provided is a novel lithium complex oxide containing molybdenum. A complex oxide represented by the following compositional formula: Li.sub.xM.sub.yMo.sub.zO wherein M is one or two or more selected from the group consisting of Mn, Ru, Sn, Mg, Al, Ti, V, Cr, Fe, Co, Ni, Cu, and Zn; x is in the range of 0.60 to 0.75; y is in the range of 0.15 to 0.25; and z is in the range of 0.075 to 0.20.