A process for converting natural calcium carbonate into precipitated calcium carbonate, involving treating the natural calcium carbonate with a sulfate to produce a gypsum and reacting the gypsum with at least one carbonate source to produce precipitated calcium carbonate. The crystalline polymorph, particle size, and various other characteristics of the precipitated calcium carbonate are controlled by varying conditions during the reacting. Since the natural calcium carbonate is not calcined, the process relates to a low energy method of producing precipitated calcium carbonate of controlled polymorph and particle size with limestone, marble, or chalk as the calcium source.

The present application discloses a positive electrode active material including a lithium nickel cobalt manganese oxide, the molar content of nickel in the lithium nickel cobalt manganese oxide accounts for 60%-90% of the total molar content of nickel, cobalt and manganese, and the lithium nickel cobalt manganese oxide has a layered crystal structure of a space group R 3m; a transition metal layer of the lithium nickel cobalt manganese oxide includes a doping element, and the local mass concentration of the doping element in particles of the positive electrode active material has a relative deviation of 20% or less; and in a differential scanning calorimetry spectrum of the positive electrode active material in a 78% delithiation state, an initial exothermic temperature of a main exothermic peak is 200° C. or more, and an integral area of the main exothermic peak is 100 J/g or less.

A method of synthesizing bimetallic oxide nanocomposites includes the steps of: providing a first metal salt solution; adding an oxidizing agent to the first metal salt solution while degassing the solution with an inert gas; heating the first metal salt solution; adding a second metal salt solution to the heated first metal salt solution to form a reaction mixture; adding a solution comprising a poly (ionic liquid) into the reaction mixture; adding a first base into the reaction mixture; adding a second base while stirring and maintaining a temperature ranging from about 40° C. to about 65° C. to provide a solution including a bimetallic oxide nanocomposite precipitate. The first metallic salt solution can include FeCl.sub.3 dissolved in water. The second metallic salt solution can include CuCl.sub.2 dissolved in water. The bimetallic oxide nanocomposites can be combined with epoxy resin to coat a steel stubstrate.

Methods of synthesis of mesoporous silica are disclosed. The mesoporous silica synthesized herein, like SBA-15, possesses a two-dimensional, hexagonal, through-hole structure with a space group p6mm. An effective quantity of one or more water-soluble oxidized disulfide oil (ODSO) compounds are used during synthesis to impart distinct characteristics.

Oxide compositions comprising a modified structure which includes the formula ABO.sub.z. The A component may comprise at a cation of least one element selected from the group consisting of Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Pr, Nd, Gd, and Zn, and the B component may comprise a cation of at least one element selected from the group consisting of V, Cr, Mn, Fe, Co, and Ni. Batteries and supercapacitors comprising the oxide compositions of the present disclosure and methods of making the oxide compositions of the present disclosure are also provided.

According to the present invention, there are provided lithium titanate particles which exhibit an excellent initial discharge capacity and an enhanced high-efficiency discharge capacity retention rate as an active substance for non-aqueous electrolyte secondary batteries and a process for producing the lithium titanate particles, and Mg-containing lithium titanate particles.

A crystalline titanium and magnesium compound having an X-ray diffraction pattern having interplanar spacing (d-spacing) values at about 5.94, 3.10, 2.97, 2.10, 1.98, 1.82, and 1.74±0.1 angstroms may be used in protective coatings for metal or metal alloy substrates. The coatings exhibit excellent corrosion resistances and provide corrosion protection equal to or better than typical non-chromate coatings.

A lithium complex oxide includes a mixture of first particles of n1 (n1>40) aggregated primary particles and second particles of n2 (n2≤20) aggregated primary particles, the lithium complex oxide represented by Chemical Formula 1 and having FWHM (deg., 2θ) of 104 peak in XRD, defined by a hexagonal lattice having R-3m space group, in a range of Formula 1:

Li.sub.aNi.sub.xCo.sub.yMn.sub.zM.sub.1-x-y-zO.sub.2,   [Chemical Formula 1]

where M is selected from: B, Ba, Ce, Cr, F, Mg, Al, Cr, V, Ti, Fe, Zr, Zn, Si, Y, Nb, Ga, Sn, Mo, W, P, Sr, and any combination thereof, 0.9≤a≤1.3, 0.6≤x≤1.0, 0.0≤y≤=0.4, 0.0≤z≤0.4, and 0.0≤1-x-y-z≤0.4,

−0.025≤FWHM.sub.(104)−{0.04+(x.sub.first particle−0.6)×0.25}≤0.025,   [Formula 1]

where FWHM.sub.(104) is represented by Formula 2,

FWHM.sub.(104)={(FWHM.sub.Chemical Formula 1 powder(104)−0.1×mass ratio of second particles)/mass ratio of first particles}−FWHM.sub.Si powder (220).   [Formula 2]

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 present disclosure provides a method for preparing a multi-layer hexagonal boron nitride film, including: preparing a substrate; preparing a boron-containing solid catalyst, and disposing the boron-containing solid catalyst on the substrate; annealing the boron-containing solid catalyst to melt the boron-containing solid catalyst; feeding a nitrogen-containing gas and a protecting gas to an atmosphere in which the melted boron-containing solid catalyst resides, the nitrogen-containing gas reacts with the boron-containing solid catalyst to form the multi-layer hexagonal boron nitride film on a surface of the substrate. The method for preparing a multi-layer hexagonal boron nitride film can prepare a hexagonal boron nitride film having a lateral size in the order of inches and a thickness from several nanometers to several hundred nanometers on the surface of the substrate, providing a favorable basis for the application of hexagonal boron nitride in the field of two-dimensional material devices.