A particle structure of cathode material and a preparation method thereof is provided. Firstly, a precursor for forming a core is provided. The precursor includes at least nickel, cobalt and manganese. Secondly, a metal salt and a lithium ion compound are provided. The metal salt includes at least potassium, aluminum and sulfur. After that, the metal salt, the lithium ion compound and the precursor are mixed, and a mixture is formed. Finally, the mixture is subjected to a heat treatment step, and a cathode material particle structure is formed to include the core, a first coating layer coated on the core and a second coating layer coated on the first coating layer. The core includes potassium, aluminum and a Li-M-O based material. The first coating layer includes potassium and aluminum, and a potassium content of the first coating layer is higher than a potassium content of the core. The second coating layer includes sulfur.

An electrode material for a lithium ion secondary battery of the present invention is an electrode material for a lithium ion secondary battery including an electrode active material and a carbonaceous film that coats a surface of the electrode active material, in which a hydroxy group and a group which is at least one selected from a carboxyl group, a nitro group, and a sulfo group have been introduced to an outermost surface of the carbonaceous film, a ratio of a total count number of the group which is at least one selected from the carboxyl group, the nitro group, and the sulfo group to a count number of the hydroxy group is 0.001 or more and 10.000 or less when a surface of the carbonaceous film is analyzed through time-of-flight secondary ion mass spectrometry to obtain the ratio, a coating ratio of the carbonaceous film is set to 40% or more and 90% or less, and the carbonaceous film has at least one through-hole per 100 square nanometers.

A technique for exfoliating a transition metal dichalcogenide material to produce separated nano-scale platelets includes combining the transition metal dichalcogenide material with a liquid to form a slurry, wherein the transition metal dichalcogenide material includes layers of nano-scale platelets and has a general chemical formula MX.sub.2, and wherein M is a transition metal and X is sulfur, selenium, or tellurium. The slurry of the transition metal dichalcogenide material is treated with an oxidant to form peroxo-metalate intermediates on an edge region of the layers of nano-scale platelets of the transition metal dichalcogenide material. The peroxo-metalate intermediates is treated with a reducing agent to form negatively charged poly-oxo-metalates to induce separation of the transition metal dichalcogenide material into the separated nano-scale platelets of the transition metal dichalcogenide material.

The present invention is directed to a process for preparing a transition metal phosphate comprising mixing a transition metal oxide with a hypophosphite compound and heating the mixture under inert gas conditions.

Provided are a metal element-doped positive electrode active material for a high voltage and a preparation method thereof. The positive electrode active material may include a lithium cobalt oxide having a layered crystal structure; and a metal element (M) incorporated into the lithium cobalt oxide in an amount of 0.2 parts by weight to 1 part by weight with respect to 100 parts by weight of the lithium cobalt oxide, wherein the metal element (M) does not form a chemical bond with the elements of the lithium cobalt oxide, and wherein the layered crystal structure in maintained at a positive electrode potential of more than 4.5 V (based on Li potential) when fully charged.

Provided are a surface-treated inorganic powder, which satisfies the following expression (1) and the following expression (2), and a method of producing the same, and a dispersion and a resin composition each containing the surface-treated inorganic powder: ?Expression (1) 3.0?D1?50.0; ?Expression (2) 1.00?D1/D2<1.10, in the expression (1) and the expression (2), D1 represents a presence amount (?mol/m.sup.2) of double bonds contained in the surface-treated inorganic powder, and D2 represents a presence amount (?mol/m.sup.2) of double bonds contained in a washed powder, wherein the washed powder is a powder obtained by subjecting the surface-treated inorganic powder to predetermined washing treatments.

A positive electrode active material for a lithium secondary battery, a method of preparing the same, and a lithium secondary battery, the positive electrode active material including nickel, cobalt, and manganese, wherein the positive electrode active material has a core part and a surface part, an amount of manganese in the core part and the surface part is higher than 25 mol %, and amounts of nickel and cobalt in the positive electrode active material vary such that a concentration gradient of the nickel and the cobalt in a direction from the core part to the surface part is present in the positive electrode active material.

Disclosed herein is a method for preparing large soluble graphenes. The method comprises attaching one or more hindering groups to the graphene, which can prevent face-to-face graphene stacking by reducing the effects of inter-graphene attraction. The large graphenes can absorb a wide spectrum of light from UV to near infrared, and are useful in photovoltaic devices and sensitizers in nanocrystalline solar cells.

A garnet-type ion-conducting oxide configured to inhibit lithium carbonate formation on the surface of crystal particles thereof, and a method for producing an oxide electrolyte sintered body using the garnet-type ion-conducting oxide. The garnet-type ion-conducting oxide represented by a general formula (Li.sub.x-3y-z, E.sub.y, H.sub.z)L.sub.?M.sub.62 O.sub.?(where E is at least one kind of element selected from the group consisting of Al, Ga, Fe and Si; L is at least one kind of element selected from an alkaline-earth metal and a lanthanoid element: M is at least one kind of element selected from a transition element which be six-coordinated with oxygen and typical elements in groups 12 to 15 of the periodic table; 3?x?3y?z?; 0?y?0.22; C?z?2.8; 2.5???3.5; 1.5???2.5; and 11???13), wherein a half-width of a diffraction peak which has a highest intensity and which is observed at a diffraction angle (2?) in a range of from 29? to 32? as a result of X-ray diffraction measurement using CuK? radiation, is 0.164? or less.

A nanoparticle of a decomposition product of a transition metal aluminum hydride compound, a transition metal borohydride compound, or a transition metal gallium hydride compound. A process of: reacting a transition metal salt with an aluminum hydride compound, a borohydride compound, or a gallium hydride compound to produce one or more of the nanoparticles. The reaction occurs in solution while being sonicated at a temperature at which the metal hydride compound decomposes. A process of: reacting a nanoparticle with a compound containing at least two hydroxyl groups to form a coating having multi-dentate metal-alkoxides.