Compounds that can be used as cathode active materials for lithium ion batteries are described. In some embodiments, the cathode active material includes the compound Li.sub.xNi.sub.aM.sub.bN.sub.cO.sub.2 where M is selected from Mn, Ti, Zr, Ge, Sn, Te and a combination thereof; N is selected from Mg, Be, Ca, Sr, Ba, Fe, Ni, Cu, Zn, and a combination thereof; 0.9<x<1.1; 0.7<a<1; 0<b<0.3; 0<c<0.3; and a+b+c=1. Other cathode active materials, precursors, and methods of manufacture are presented.

A positive electrode active material for a non-aqueous electrolyte secondary battery that includes a lithium transition metal composite oxide having a spinel structure and containing nickel and manganese is provided. The positive electrode active material includes a first surface region having a chemical composition with a molar ratio of nickel to manganese of 0.1 or less on the surface of the lithium transition metal composite oxide.

A cathode composition for a lithium-ion cell or battery of the general formula: Li.sub.1+xMn.sub.1−xO.sub.2, wherein the composition is in the form of a single phase having a rock salt crystal structure such that an x-ray diffraction pattern of the composition has an absence of peaks below a 20 value of 35; and the value of x is greater than 0, and equal to or less than 0.3. The compound is also formulated into a positive electrode, or cathode, for use in an electrochemical cell.

A positive active material for a rechargeable lithium battery includes a lithium nickel-based composite oxide including a secondary particle in which a plurality of plate-shaped primary particles are agglomerated; and a lithium manganese composite oxide having at least two crystal lattice structures, wherein the secondary particle has a regular array structure in which (003) planes of the primary particles are oriented in a vertical direction with respect to the surface of the secondary particle.

Supplemental lithium can be used to stabilize lithium ion batteries with lithium rich metal oxides as the positive electrode active material. Dramatic improvements in the specific capacity at long cycling have been obtained. The supplemental lithium can be provided with the negative electrode, or alternatively as a sacrificial material that is subsequently driven into the negative electrode active material. The supplemental lithium can be provided to the negative electrode active material prior to assembly of the battery using electrochemical deposition. The positive electrode active materials can comprise a layered-layered structure comprising manganese as well as nickel and/or cobalt.

A process for preparing a metal oxide-containing powder that comprises conducting spray pyrolysis that comprises aerosolizing a slurry that comprises solidphase particles in a liquid that comprises at least one precursor compound, which comprises one or more metallic elements of at least one metal oxide, to form droplets of said slurry, and calcining the droplets to at least partially decompose the at least one precursor compound and form the metal oxide-containing powder having a non-hollow morphology.

A cathode active material including a lithium transition metal oxide of Chemical Formula 1:
Li.sub.2-xMe.sub.xM.sub.yMn.sub.1-yO.sub.3-δ  Chemical Formula 1
wherein 0≦x≦0.2, 0≦y≦0.2, 0<x+y≦0.4, and 0≦δ<1, and Me and M are each independently one or more metals selected from magnesium (Mg), calcium (Ca), strontium (Sr), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), tungsten (W), technetium (Tc), rhenium (Re), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), aluminum (Al), gallium (Ga), indium (In), silicon (Si), germanium (Ge), tin (Sn), and a rare earth element.

The present invention discloses a method for preparing lithium-rich manganese-based cathode material. The method comprises: dispersing α-MnO.sub.2 micron particles, a nickel salt and a lithium-containing compound in a solvent to obtain a mixture, then evaporating the mixture to remove the solvent, and calcining the solid product obtained from the evaporation; wherein the lithium-containing compound is a lithium salt and/or lithium hydroxide. The present invention also provides a lithium-rich manganese-based cathode material prepared by the above method. The present invention also provides a lithium-ion battery of which anode material contains the foregoing lithium-rich manganese-based anode material. The lithium-rich manganese-based cathode material provided by the present invention has high rate capability and prolonged cycle stability.

Supplemental lithium can be used to stabilize lithium ion batteries with lithium rich metal oxides as the positive electrode active material. Dramatic improvements in the specific capacity at long cycling have been obtained. The supplemental lithium can be provided with the negative electrode, or alternatively as a sacrificial material that is subsequently driven into the negative electrode active material. The supplemental lithium can be provided to the negative electrode active material prior to assembly of the battery using electrochemical deposition. The positive electrode active materials can comprise a layered-layered structure comprising manganese as well as nickel and/or cobalt.

A mixed ionic and electronic conductor represented by Formula 1:
T.sub.xVa.sub.yA.sub.1-x-yM.sub.zO.sub.3-δ,
wherein T includes at least one monovalent cation, A includes at least one of a monovalent cation, a divalent cation, and a trivalent cation, M includes at least one of a trivalent cation, a tetravalent cation, and a pentavalent cation, M is an element other than Ti and Zr, Va is a vacancy, δ is an oxygen vacancy, 0<x, y≤0.25, 0<z<1, and 0≤δ≤1.