The invention relates to a mechanochemical process to produce exfoliated nanoparticles comprising the steps of providing a solid feedstock comprising a carbonaceous and/or mineral-based material; providing a flow of an oxidizing gas; introducing the solid feedstock and the flow of an oxidizing gas into a mechanical agitation unit, subjecting the material of the solid feedstock in the presence of the oxidizing gas to a mechanical agitation operation in the mechanical agitation unit at a pressure of at least 1 atm (15 psi).

The invention further relates to nanoparticles obtainable by the mechanochemical process and to the use of such nanoparticles.

A positive electrode for a rechargeable lithium battery includes a positive active material including small particle diameter monolith particles having a particle diameter of about 1 μm to about 8 μm and including a first nickel-based lithium metal oxide, and large particle diameter secondary particles having a particle diameter of about 10 μm to about 20 μm and including a second nickel-based lithium metal oxide. An X-ray diffraction peak intensity ratio (I(003)/I(104)) of the positive electrode is greater than or equal to about 3. A rechargeable lithium battery includes the positive electrode.

The present disclosure relates to a positive electrode active material comprising a first particle group and a second particle group, wherein the first particle group consists of a plurality of first particles, each first particle includes one to ten single particles, the second particle group consists of a plurality of second particles, each second particle includes an aggregation-based particle, and each aggregation-based particle is formed of 50 or more primary particles aggregated to each other.

The present invention provides that powder is mainly constituted from secondary particles of hydroxyapatite. The secondary particles are obtained by drying a slurry containing primary particles of hydroxyapatite and aggregates thereof and granulating the primary particles and the aggregates. A bulk density of the powder is 0.65 g/mL or more and a specific surface area of the secondary particles is 70 m.sup.2/g or more. The powder of the present invention has high strength and is capable of exhibiting superior adsorption capability when it is used for an adsorbent an adsorption apparatus has.

The invention relates to a mechanochemical process to produce exfoliated nanoparticles comprising the steps of providing a solid feedstock comprising a carbonaceous and/or mineral-based material; providing a flow of an oxidizing gas; introducing the solid feedstock and the flow of an oxidizing gas into a mechanical agitation unit, subjecting the material of the solid feedstock in the presence of the oxidizing gas to a mechanical agitation operation in the mechanical agitation unit at a pressure of at least 1 atm (15 psi). The invention further relates to nanoparticles obtainable by the mechanochemical process and to the use of such nanoparticles.

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]

A spinel-structured lithium manganese-based 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 and includes at least one coating element selected from the group consisting of aluminum, titanium, tungsten, boron, fluorine, phosphorus, magnesium, nickel, cobalt, iron, chromium, vanadium, copper, calcium, zinc, zirconium, niobium, molybdenum, strontium, antimony, bismuth, silicon, and sulfur, and a positive electrode and a lithium secondary battery which include the positive electrode active material,
Li.sub.1+aMn.sub.2−bM.sup.1.sub.bO.sub.4−cA.sub.c  [Formula 1] wherein, in Formula 1, M.sup.1 is at least one metallic element including lithium (Li), A is at least one element selected from the group consisting of fluorine, chlorine, bromine, iodine, astatine, and sulfur, 0≤a≤0.2, 0<b≤0.5, and 0≤c≤0.1.

A positive electrode active material includes a lithium composite transition metal oxide represented by Formula 1 described in the present specification and satisfies Equation (1) described in the present specification, wherein an average particle diameter D.sub.50 of a secondary particle is in a range of 1 .Math.m to 8 .Math.m. A method of preparing the same, and a positive electrode material including the same are also provided.

A positive electrode material having particles with P6.sub.3mc crystal phase structure; and a particle size distribution frequency graph of the positive electrode material comprisecomprises a first peak and a second peak. The positive electrode material has a stable crystal structure, and the electrochemical apparatus using the positive electrode material can maintain high capacity and good cycling performance at a high voltage.

The present invention relates to a positive electrode active material and a lithium secondary battery including the same, and more particularly, to a positive electrode active material which exhibits a predetermined peak intensity ratio and a predetermined voltage ratio in a graph illustrating the voltage (V) and the battery capacity (Q) at the 3.sup.rd cycle and having an X axis indicating the voltage (V) and a Y axis indicating a value (dQ/dV) obtained by differentiating the battery capacity (Q) with respect to the voltage (V) when charging/discharging is performed under predetermined conditions, and a lithium secondary battery including the same.