Provided is a method of manufacturing MoS.sub.2 having a 1T crystal structure. The method includes performing phase transition from a 2H crystal structure of MoS.sub.2 to the 1T crystal structure by reacting MoS.sub.2 having the 2H crystal structure with CO gas. The phase transition includes annealing the MoS.sub.2 having the 2H crystal structure in an atmosphere including CO gas.

Provided are electrochemically active secondary particles that provide excellent capacity and improved cycle life. The particles are characterized by selectively enriched grain boundaries where the grain boundaries are enriched with Al and Co. The enrichment with Al 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.

A positive electrode active material for a lithium secondary cell, having a layered structure and comprising at least nickel, cobalt and manganese, the positive electrode active material satisfying requirements (1), (2) and (3) below: (1) a composition represented by a composition formula: Li[Li.sub.x(Ni.sub.Co.sub.Mn.sub.M.sub.).sub.1-x]O.sub.2, wherein 0x0.10, 0.30<0.34, 0.30<0.34, 0.32<0.40, 00.10, <, +++=1, M represents at least one metal selected from the group consisting of Fe, Cu, Ti, Mg, Al, W, Zn, Sn, Zr, Ga and V; (2) a secondary particle diameter of 2 m or more and 10 m or less; and (3) a maximum peak value in a pore diameter range of 90 nm to 150 nm in a pore diameter distribution determined by mercury porosimetry.

Vessels selected from crucibles, pans, open cups and saggars essentially comprising of two components, from which (A) one component being a ceramic matrix composite, and (B) the second component being from metal or alloy, and wherein component (A) is the inner one.

A lithium cobalt-based positive electrode active material is provided. The lithium cobalt-based positive electrode active material includes a core portion including a lithium cobalt-based oxide represented by Formula 1 and a shell portion including a lithium cobalt-based oxide represented by Formula 2, wherein the lithium cobalt-based positive electrode active material includes 2500 ppm or more, preferably 3000 ppm or more of a doping element M based on the total weight of the positive electrode active material. An inflection point does not appear in a voltage profile measured during charging/discharging a secondary battery including the lithium cobalt-based positive electrode active material.

A positive electroactive material for a lithium-ion battery can have a tap density ranging from 2.50 to 2.90 g/cm.sup.3, a Span value ranging from 1.04 to 1.68 and/or a capacity ranging from 195 to 210 mAh/g obtained using a discharging current of C/5 current rate. The material can have a formula Li.sub.a[Ni.sub.xMn.sub.yCo.sub.1xy].sub.zM.sub.1zO.sub.2, wherein a is between approximately 1.02 and 1.07, x is between approximately 0.60 to 0.82, y is between approximately 0.09 to 0.20, z is between approximately 0.95 to 1.0, and 1xy is greater than 0. A cost-effective and large-scale synthetic method for preparing the positive electroactive material, an electrochemical cell containing the positive electroactive material, and a battery comprising one or more lithium ion electrochemical cells are also described.

A positive electrode material for nonaqueous secondary batteries includes lithium transition metal composite oxide particles containing at least one of cobalt and nickel; and titanium silicide particles. The lithium transition metal composite oxide particles have a layer structure. The lithium transition metal composite oxide particles and the titanium silicide particles are present as particles substantially independent from each other. The titanium silicide particles have an average particle diameter of 4.0 m or less. The titanium silicide particles are contained at a content ratio of titanium of 1.2 mol % or less with respect to the lithium transition metal composite oxide particles.

Single crystals of a new noncentrosymmetric polar oxysulfide SrZn.sub.2S.sub.2O (s.g. Pmn2.sub.1) grown in a eutectic KFKCl flux with unusual wurtzite-like slabs consisting of close-packed corrugated double layers of ZnS.sub.3O tetrahedra vertically separated from each other by Sr atoms and methods of making same.

A positive active material for a rechargeable lithium battery includes a lithium nickel-based composite oxide and a lithium manganese composite oxide, wherein the positive active material includes a surface-modifying layer including lithium fluoride on the surface of at least one of the lithium nickel-based composite oxide and the lithium manganese composite oxide. The lithium nickel-based composite oxide includes a secondary particle in which a plurality of plate-shaped primary particles are agglomerated, and the secondary particle has a regular array structure in which (003) planes of the plurality of primary particles are aligned or oriented normal to the surface of the secondary particle. The lithium manganese composite oxide is present in two or more types of crystal lattice structures.

The present disclosure generally relates to compositions comprising substrate-free 2D crystalline nanomaterials of binary compounds of formula (M).sub.x(Te).sub.y, and the method of making and using the substrate-free crystalline 2D crystalline nanomaterial.