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.

The present invention pertains to a hydrous silica for rubber-reinforcing filler, having a BET specific surface area ranging from 230 to 350 m.sup.2/g; the volume average particle diameter (D50) measured by the laser diffraction method after dispersing 50 ml of a hydrous silica slurry adjusted to 4% by weight with an ultrasonic homogenizer having an output of 140 W for 10 minutes is 3.0 μm or less; and the top 10% of particles (D90) in the particle size distribution is 10.0 μm or less. This invention provides a hydrous silica capable of further improving reinforcing properties of a rubber, particularly the wear resistance by improving dispersibility of the hydrous silica in the rubber in addition to rubber reinforcing properties obtained by a high BET specific surface area.

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.

Previous hybrid-anion and cation-redox (HACR) cathodes were limited in cycling performance by irreversible anionic redox reactions caused by the loss of anions. To overcome this limitation, a lithium (Li) transition metal (M) oxide particle is described having a Li concentration gradient. In one example, the particle includes a Li-rich core region that provides capacity and energy density due anionic and cationic contributions and a Li-poor surface region surrounding the core region to inhibit anionic activity and thus substantially reduce the loss of anions. A gradient region disposed between the core and surface regions has a Li concentration profile that varies from a first Li concentration in the core region to a second Li concentration in the surface region. A high-temperature leaching method may be used to leach LiO from a Li-rich Li.sub.1+xM.sub.1−XO.sub.2 particle, thus forming a coherent Li gradient with a stabilized layered structure.

Presently disclosed is a multi-layered carbon-based scaffolded structure having a conductive substrate. A first film is deposited on the conductive substrate and includes: a first concentration of three-dimensional (3D) carbon-based particles comprising: a plurality of conductive 3D aggregates formed of graphene sheets that are sintered together to define a 3D hierarchical open porous structure with mesoscale structuring in combination with micron-scale fractal structuring that is also configured to provide conduction between contact points of the graphene sheets. A porous arrangement is formed in the 3D hierarchical open porous structure and contains a liquid electrolyte configured to provide ion transport through a plurality of interconnected porous channels. The first film is configured to provide a first conductivity. A second film is deposited on the first film and comprising a second concentration of 3D carbon-based particles. The second film configured to provide a second conductivity lower than the first conductivity.

A method for preparing a N(M)C-based positive electrode materials according to the present invention comprises the following steps: —Precipitation of a metal (at least Ni— and Co—, preferably comprising Mn—) bearing precursor (MBP), —Fractionation of the MBP in a first (A) fraction and at least one second (B) fraction, —Lithiation of each of the first and second fraction, wherein the A fraction is converted into a first polycrystalline lithium transition metal oxide-based powder and the B fraction(s) is(are) converted into a second lithium transition metal oxide-based powder and, and —Mixing the first and second monolithic lithium transition metal oxide-based powder to obtain the N(M)C-based positive electrode material.

The present invention relates to a positive electrode active material and a lithium secondary battery including the same, and more particularly, to a bimodal-type positive electrode active material including a first lithium composite oxide, which is a small particle, and a second lithium composite oxide, which is a large particle, these particles having different particle diameters, wherein the positive electrode active material makes it possible to prevent deterioration in electrochemical properties and stability thereof, which are generated due to non-uniform formation of a coating layer at least partially coating surfaces of the small and large particles, a positive electrode including the positive electrode active material, and a lithium secondary battery using the same.

The present invention relates to a process for preparing zeolite crystals having a multimodal particle size distribution, and the sizes of which are between 0.02 μm and 20 μm, said process comprising a first introduction of one or more seeding agents into the tubular reactor or upstream of the tubular reactor, and at least one second introduction of one or more, identical or different, seeding agents into the tubular reactor.

A positive electrode active substance, wherein: the average primary particle diameter of an Ni-containing lithium complex oxide A is 0.5 μm or greater, and is greater than the average primary particle diameter (0.05 μm or greater) of an Ni-containing lithium complex oxide B; and the average secondary particle diameter of the Ni-containing lithium complex oxide A is 2-6 μm, and is less than the average secondary particle diameter (10-20 μm) of the Ni-containing lithium complex oxide B. The Ni-containing lithium complex oxides A, B contain 55 mol % or more of Ni relative to the total mol of metal elements excluding Li, have a crystallite diameter of 100-200 nm, and are such that the disorder of elemental Ni is 3% or less.

The present invention pertains to a hydrous silica for rubber-reinforcing filler, having a BET specific surface area ranging from 230 to 350 m.sup.2/g; the volume average particle diameter (D50) measured by the laser diffraction method after dispersing 50 ml of a hydrous silica slurry adjusted to 4% by weight with an ultrasonic homogenizer having an output of 140 W for 10 minutes is 3.0 μm or less; and the top 10% of particles (D90) in the particle size distribution is 10.0 μm or less. This invention provides a hydrous silica capable of further improving reinforcing properties of a rubber, particularly the wear resistance by improving dispersibility of the hydrous silica in the rubber in addition to rubber reinforcing properties obtained by a high BET specific surface area.