The invention provides primary batteries that incorporate a desodiated sodium transition metal oxide into the positive electrode (a cathode). Batteries of the invention using a desodiated sodium transition metal oxide in the cathode exhibit discharge voltages, battery capacities, and energy densities higher than a traditional Zn—MnO.sub.2 dry cell battery, such as a commercially available AA battery. These batteries are also advantageous over comparable lithium ion batteries due to the high abundance and low cost of sodium precursor materials with similar electrical performance.

According to one embodiment of the present invention, a positive electrode active material with high charge and discharge capacity is provided. Alternatively, a positive electrode active material with high charge and discharge voltage is provided. Alternatively, a positive electrode active material with little deterioration is provided. To improve the reliability of the positive electrode active material, the surface of the positive electrode active material is prevented from reacting with an electrolyte solution and being reduced. The provision of a projection on part of the positive electrode active material surface decreases the reduction of the positive electrode active material surface from reacting with the electrolyte solution, thereby improving the cycle performance.

A nickel-based active material for a lithium secondary battery includes a porous inner portion having closed pores and an outer portion, wherein the porous inner portion has a density less than that of the outer portion, and the nickel-based active material has a net density of 4.7 g/cc or less. A method of preparing the same, and a lithium secondary battery including a positive electrode including the nickel-based active material are provided.

Provided are electrochemically active secondary particles that provide excellent capacity and improved cycle life. The particles are characterized by a plurality of nanocrystals with small average crystallite size. The reduced crystallite size reduces impedance generation during cycling thereby improving capacity and cycle life. Also provided are methods of forming electrochemically active materials, as well as electrodes and electrochemical cells employing the secondary particles.

The invention is directed towards an electrochemically active cathode material for a battery. The electrochemically active cathode material includes a non-stoichiometric beta-delithiated layered nickel oxide. The non-stoichiometric beta-delithiated layered nickel oxide has a chemical formula. The chemical formula is L.sub.ixA.sub.yNi.sub.1+a−zM.sub.zO.sub.2.Math.nH.sub.2O where x is from about 0.02 to about 0.20; y is from about 0.03 to about 0.20; a is from about 0.02 to about 0.2; z is from about 0 to about 0.2; and n is from about 0 to about 1. Within the chemical formula, A is an alkali metal. The alkali metal includes potassium, rubidium, cesium, and any combination thereof. Within the chemical formula, M comprises an alkaline earth metal, a transition metal, a non-transition metal, and any combination thereof.

A cathode active material of formula LiNi.sub.xMn.sub.yAl.sub.zM.sub.αO.sub.2-εB.sub.ε or NaNi.sub.x′Mn.sub.y′Al.sub.z′M′.sub.α′O.sub.2-ε′B.sub.ε′, wherein M is a combination of Ti, and Mg; M′ is Ti, Mg, or a combination of thereof; B is selected from the group of F, S, Se, or Cl; 0.8<x<1, 0<y<0.2, 0<z≤0.2, 0≤α≤0.2, 0≤ε≤0.1, 0.5<x′<1, 0<y′<0.5, 0<z′≤0.2, 0≤α′≤0.2, and 0≤ε′≤0.1. The particle is a single crystal, a single particle, or a secondary particle comprising a plurality of primary particles; and the particle is a uniform composition or a concentration gradient composition.

Provided are electrochemically active secondary particles that provide excellent capacity and improved cycle life. The particles are characterized by a plurality of nanocrystals with small average crystallite size. The reduced crystallite size reduces impedance generation during cycling thereby improving capacity and cycle life. Also provided are methods of forming electrochemically active materials, as well as electrodes and electrochemical cells employing the secondary particles.

Provided is a composite metal oxide which is represented by Formula (1) and has an α-NaFeO.sub.2 type crystal structure, in which a peak half value width of a (104) plane to be measured by powder X-ray diffraction is 0.250° or less at 2θ.
Na.sub.xM.sup.1.sub.r(Fe.sub.yNi.sub.zMn.sub.wM.sub.1−y−z−w)O.sub.2±δ  (1) (in Formula (1), M represents any one or more elements selected from the group consisting of B, Si, V, Ti, Co, Mo, Pd, Re, Pb, and Bi, M.sup.1 represents any one or more elements selected from the group consisting of Mg and Ca, and relations 0≤r≤0.1, 0.5≤x≤1.0, 0.1≤y≤0.5, 0<z<0.4, 0<w<0.4, 0≤δ≤0.05, and y+z+w≤1 are satisfied).

A method for producing a positive electrode material for a nonaqueous secondary battery includes the steps of mixing a compound containing lithium, a compound containing nickel and BaTiO.sub.3 to form a mixed material; and sintering the mixed material to form a lithium transition metal composite oxide.

The invention relates to a method of preparing a sodium metal oxide material comprising Na.sub.xM.sub.yCo.sub.zO.sub.2-δ, where M is one or more of the following elements: Mn, Cu, Ti, Fe, Mg, Ni, V, Zn, Al, Li, Sn, Si, Ga, Ge, Sb, W, Zr, Nb, Mo, Ta, 0.7≤x≤1.3, 0.9≤y≤1.1, 0≤z<0.15, 0≤δ≤0.2 and wherein the average length of primary particles of said sodium metal oxide material is between 2 and 10 μm, preferably between 5 and 10 μm. The invention also relates to such a material.