Nanowire synthesis and one dimensional nanowire synthesis of titanates and cobaltates. Exemplary titanates and cobaltates that are fabricated and discussed include, without limitation, strontium titanate (SrTiO.sub.3), barium titanate (BaTiO.sub.3), lead titanate (PbTiO.sub.3), calcium cobaltate (Ca.sub.3Co.sub.4O.sub.9) and sodium cobaltate (NaCo.sub.2O.sub.4).

Provided are a positive active material, a positive electrode including the same, and a lithium secondary battery including the positive electrode. The positive active material includes lithium cobalt oxide containing a metal element, and the lithium cobalt oxide containing a metal element has a ratio of a peak intensity of the O3 phase to a peak intensity of the H1-3 phase, I.sub.O3/I.sub.H1-3, that is greater than 1 in a X-ray diffraction (XRD) analysis spectrum using Cu-Kα radiation. Accordingly, a lithium secondary battery including the positive active material may have improved lifespan characteristics even at a high voltage.

The present invention relates to an oxide active material surface-treated with a lithium compound, a method for preparing the same, and an all-solid lithium secondary battery capable of effectively suppressing an interface reaction in a solid electrolyte by adopting the same. In the all-solid lithium secondary battery comprising an electrode containing a positive electrode active material and a sulfide-based solid electrolyte, the positive electrode active material according to the present invention can significantly improve battery characteristics since a coating layer formed of a lithium compound is formed while surrounding a particle surface to act as a functional coating layer which suppresses the interface reaction of the sulfide-based solid electrolyte and the electrode. In addition, in cases where the active material is synthesized and coated with a lithium compound at the same time, a lithium salt and a transition metal salt are dissolved in a solvent through stirring, to prepare a solution, followed by drying and heat treatment, and here, the prepared active material has a form in which a mixture generated from an excessive amount of lithium salt which is synthesized and then remains on the particle surface having a structure capable of absorbing and releasing lithium is coated on the particle surface to form a coating layer. In addition, in cases where the previously synthesized active material is coated with a lithium compound, the active material and a lithium salt are dissolved in a solvent through stirring, followed by drying and heat-treatment, and here, the prepared active material has a form in which a mixture generated from an excessive amount of lithium salt which is synthesized and then remains on the particle surface having a structure capable of absorbing and releasing lithium is coated on the particle surface to for m a coating layer.

The present invention provided a positive electrode active material for a lithium secondary battery including lithium cobalt oxide particles. The lithium cobalt oxide particles include lithium deficient lithium cobalt oxide having Li/Co molar ratio of less than 1, belongs to an Fd-3m space group, and having a cubic crystal structure, in surface of the particle and in a region corresponding to a distance from 0% to less than 100% from the surface of the particle relative to a distance (r) from the surface to the center of the particle. In the positive electrode active material for a lithium secondary battery according to the present invention, the intercalation and deintercalation of lithium at the surface of a particle may be easy, and the output property and rate characteristic may be improved when applied to a battery.

Provided is a method for preparing a positive electrode active material for a lithium secondary battery, the method comprising: mixing and reacting a nickel source, a cobalt source, and an aluminum source, ammonia water, sucrose, and a pH adjusting agent to prepare a mixed solution; drying and oxidizing the mixed solution to prepare a positive electrode active material precursor; and adding a lithium source to the positive electrode active material precursor and firing them to prepare a positive electrode active material for a lithium secondary battery.

The present disclosure relates to a positive electrode material including a spinel-structured lithium manganese-based first positive electrode active material and a lithium nickel-manganese-cobalt-based second positive electrode active material, wherein the first positive electrode active material includes a lithium manganese oxide represented by Formula 1 and a coating layer which is disposed on a surface of the lithium manganese oxide, the second positive electrode active material is represented by Formula 2, and an average particle diameter of the second positive electrode active material is greater than an average particle diameter of the first positive electrode active material, and a positive electrode and a lithium secondary battery which include the positive electrode material:
Li.sub.1+aMn.sub.2−bM.sup.1.sub.bO.sub.4−cA.sub.c  [Formula 1]
Li.sub.1+x[Ni.sub.yCo.sub.zMn.sub.wM.sup.2.sub.v]O.sub.2−pB.sub.p  [Formula 2]

A positive electrode active material has a small difference in a crystal structure between the charged state and the discharged state. For example, the crystal structure and volume of the positive electrode active material, which has a layered rock-salt crystal structure in the discharged state and a pseudo-spinel crystal structure in the charged state at a high voltage of approximately 4.6 V, are less likely to be changed by charging and discharging as compared with those of a known positive electrode active material. In order to form the positive electrode active material having the pseudo-spinel crystal structure in the charged state, it is preferable that a halogen source such as a fluorine and a magnesium source be mixed with particles of a composite oxide containing lithium, a transition metal, and oxygen, which is synthesized in advance, and then the mixture be heated at an appropriate temperature for an appropriate time.

A lithium cobalt-based oxide cathode active material powder comprising particles having a median particle size D50 of greater than or equal to 20 μm, preferably 25 μm, and less than or equal to 45 μm, said particles having an averaged circularity of greater than or equal to 0.85 and less than or equal to 1.00, said particles having a general formula Li.sub.1+aCo.sub.1-x-y-zAl.sub.xM′.sub.yMe.sub.zO.sub.2, wherein M′ and Me comprise at least one element of the group consisting of: Ni, Mn, Nb, Ti, W, Zr, and Mg, with −0.01≤a≤0.01, 0.002≤x≤0.050, 0≤y≤0.020 and 0≤z≤0.050, said lithium cobalt-based oxide particles having a R-3m structure and (018) diffraction peak asymmetry factor A.sub.D(018) of greater than or equal to 0.85 and less than or equal to 1.15, said diffraction peak asymmetry factor being obtained by a synchrotron XRD spectrum analysis with an emission wavelength λ value equal to 0.825 Å.

The present technology relates to electrode materials comprising an electrochemically active material, wherein the electrochemically active material comprises a P2-type or a O3-type layered sodium metal oxide. The electrochemically active material is of formula Na.sub.xMO.sub.2, wherein 0.5≤x≤1.0 and M is selected from Co, Mn, Fe, Ni, Ti, Cr, V, Cu, Sb and their combinations. Also described are electrodes, electrochemical cells and batteries comprising the electrode materials.

A positive electrode active material that has high capacity and excellent charge and discharge cycle performance for a secondary battery is provided. A positive electrode active material that inhibits a decrease in capacity in charge and discharge cycles is provided. A high-capacity secondary battery is provided. A secondary battery with excellent charge and discharge characteristics is provided. A highly safe or reliable secondary battery is provided. A positive electrode active material contains lithium, cobalt, oxygen, and aluminum and has a crystal structure belonging to a space group R-3m when Rietveld analysis is performed on a pattern obtained by powder X-ray diffraction. In analysis by X-ray photoelectron spectroscopy, the number of aluminum atoms is less than or equal to 0.2 times the number of cobalt atoms.