A secondary battery having an improved life characteristics is provided by the use of a positive electrode active material for a secondary battery, comprising (a) a surface layer comprising a lithium metal composite oxide having a spinel crystal structure represented by space group Fd-3m, and (b) an internal portion comprising a lithium metal composite oxide having a spinel crystal structure represented by space group P4.sub.332.

A process for producing a ceramic material including providing an aqueous solution comprising at least one transition metal ion and one or more further transition metal ion and/or one or more additional ion; adding to the aqueous solution a quaternary ammonium or phosphonium hydroxide comprising at least one alkyl group containing about 8 or more carbon atoms to form a combined aqueous solution; mixing the combined aqueous solution to form a gel; transferring the formed gel to a furnace; and heating the formed gel to a temperature sufficient for a time sufficient to calcine the gel to form a solid ceramic material. The process in accordance with the present invention provides an improved ceramic material, in some embodiments of which is suitable for use in the cathode material of a lithium ion battery.

According to one embodiment, a nonaqueous electrolyte battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte is provided. The positive electrode includes an active material including Li.sub.1xMn.sub.2yzAl.sub.yM.sub.zO.sub.4 (0.1x1, 0.20y0.35, 0z0.1, M is at least one metal selected from Mg, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, and Sn). The negative electrode includes an active material including a first oxide represented by Li.sub.4+aTi.sub.5O.sub.12 (0.5a3) and a second oxide of at least one element selected from Al, Co, Cr, Cu, Fe, Mg, Ni, Zn, and Zr. The second oxide is included in an amount of from 300 ppm to 5000 ppm relative to a weight of the first oxide.

A method of preparing a homogeneously dispersed chlorine-modified lithium manganese-based AB.sub.2O.sub.4 spinel cathode material is provided. Furthermore, a homogeneously dispersed chlorine-modified lithium manganese-based AB.sub.2O.sub.4 spinel cathode material is provided. In addition, a lithium or lithium ion rechargeable electrochemical cell is provided incorporating a homogeneously dispersed chlorine-modified lithium manganese-based AB.sub.2O.sub.4 spinel cathode material in a positive electrode.

Provided is a spinel-type lithium metal composite oxide that makes it possible to achieve excellent high-temperature storage characteristics when used as a positive electrode active material of a lithium battery. The spinel-type (Fd-3m) lithium metal composite oxide is characterized by the oxygen occupancy (OCC) thereof as determined by the Rietveld method being 0.965-1.000, the lattice strain thereof as determined by the Williamson-Hall method being 0.015-0.090, and the ratio (Na/Mn) of the molar content of Na to the molar content of Mn satisfying 0.00<Na/Mn<1.0010.sup.2.

Lithium manganese oxide material used in lithium ion battery is disclosed herein. The lithium manganese oxide material may be doped with suitable dopant. The lithium manganese oxide material may be represented by a first formula of Li.sub.1+xM.sub.yMn.sub.2yxO.sub.4, wherein the value of x, in the first formula, satisfies a relation 0.1<x<0.3 and the value of y, in the first formula, satisfies a relation a relation 0y0.2. The lithium manganese oxide material may further be coated with a shell capping layer. The shell capping layer may be made of a carbon or a compound having a second formula, Li.sub.1+xM.sub.yMn.sub.2yxO.sub.4. In an aspect, the value of x, in the second formula, may satisfy a relation 0.1<x<0.3. Further, the value of y, in the second formula, may satisfy a relation 0y0.2.

Provided is a method for manufacturing a cathode active material for a lithium secondary battery, the method including heat-treating a precursor aqueous solution containing a lithium precursor, a transition metal precursor, and an organic acid containing a carboxyl group, and having a chelation index (C.I) value less than 1 and 0.5 or more, wherein the chelation index value is defined by transmittance of a peak located in a wavenumber from 1,700 to 1,710 cm.sup.1 and transmittance of a peak located in a wavenumber from 1,550 to 1,610 cm.sup.1 in Fourier transform infrared (FTIR) spectroscopy spectrum.

The anode and/or the cathode of a lithium-transporting or sodium-transporting electrochemical battery cell or capacitor cell are formed of small (micrometer-size) electrode material particles having one or more channels extending through substantially each electrode particle. The through-channels are formed in the electrode particles as the particles are being formed from precursor materials. Channel-forming fibers are mixed with the electrode precursor materials when the electrode particles are being formed, and the channel forming material is removed from the formed electrode particles to leave through channels in the particles that may subsequently be infiltrated with an electrolyte for the cell.

A method of producing an active material powder includes (i) an attachment step of obtaining a powder including an active material particle, which stores and releases lithium ions at a potential of 4.5 V or higher based on Li, and a coating layer precursor, which is attached to a surface of the active material particle, by attaching an alkoxide solution containing lithium ions and niobium ions to the surface of the active material particle and drying the attached alkoxide solution; and (ii) a heating step of forming a coating layer on the surface of the active material particle by heating the powder obtained in the attachment step to be within a temperature range of 120 C. to 200 C.

Provided are a cathode active material including polycrystalline lithium manganese oxide and a sodium-containing coating layer on a surface of the polycrystalline lithium manganese oxide, and a method preparing the same. Since the cathode active material according to an embodiment of the present invention may prevent direct contact between the polycrystalline lithium manganese oxide and an electrolyte solution by including the sodium-containing coating layer on the surface of the polycrystalline lithium manganese oxide, the cathode active material may prevent side reactions between the cathode active material and the electrolyte solution. In addition, since limitations, such as the Jahn-Teller distortion and the dissolution of Mn.sup.2+, may be addressed by structurally stabilizing the polycrystalline lithium manganese oxide, tap density, life characteristics, and charge and discharge capacity characteristics of a secondary battery may be improved.