Provided is a method for preparing lead iodide, which controls the crystal form of lead iodide through temperature, including: dissolving a lead compound in a first acid solution and adding an iodine compound to form a reaction solution including the first lead iodide; and heating the reaction solution to a temperature of 60° C. or more and standing at a constant temperature, to obtain the second lead iodide, wherein a peak intensity of the (003) crystal plane of the second lead iodide is greater than or equal to a peak intensity of the (110) crystal plane. Provided is also a method for preparing the perovskite film.

A negative electrode active material tor a secondary battery includes a silicate composite particle including crystalline silicon particles, an amorphous phase comprising an Li element, an O element, and an Si element, and a silicon oxide phase, wherein the silicon oxide phase and the silicon particles are dispersed in the amorphous phase.

A nonaqueous electrolyte energy storage device according to one aspect of the present invention is a nonaqueous electrolyte energy storage device including a positive electrode having positive active material particles, in which the positive active material particles contain a lithium transition metal composite oxide having an α-NaFeO.sub.2 structure, the lithium transition metal composite oxide contains at least one of nickel and cobalt, and manganese, a content of lithium with respect to a transition metal in the lithium transition metal composite oxide exceeds 1.0 in terms of a molar ratio, a diffraction peak is present in a range of 20° or more and 22° or less in an X-ray diffraction diagram of the lithium transition metal composite oxide using a CuKα ray, and the positive active material particles contain aluminum.

A negative electrode material includes silicon-based particles and graphite particles. In a case that a D.sub.n50/D.sub.v50 ratio of the graphite particles is A and a D.sub.n50/D.sub.v50 ratio of the silicon-based particles is B, the following conditional expressions (1) to (3) are satisfied: 0.1≤A≤0.65 (1); 0.3≤B≤0.85 (2); and B>A (3), where, D.sub.v50 is a particle diameter of particles measured when a cumulative volume fraction in a volume-based distribution reaches 50%, and D.sub.n50 is a particle diameter of particles measured when a cumulative number fraction in a number-based distribution reaches 50%. The present invention further provides a negative electrode plate, a lithium-ion secondary battery or electrochemical device containing the negative electrode plate, and an electronic device containing the lithium-ion secondary battery and/or electrochemical device.

The present invention relates to an oxide sintered material that can be used suitably as a sputtering target for forming an oxide semiconductor film using a sputtering method, a method of producing the oxide sintered material, a sputtering target including the oxide sintered material, and a method of producing a semiconductor device 10 including an oxide semiconductor film 14 formed using the oxide sintered material.

A method for preparing high nickel lithiated metal oxides that includes selecting one or more nickel precursors; at least one non-corrosive lithium salt; and a plurality of metal oxide or hydroxide precursors. The metal precursors and lithium salts are mixed together to form a mixture comprising:

##STR00001##

wherein x = 1.0 - 1.1, 0.80 ≤ y ≤ 0.90, 0.03 < z ≤ 0.15, and 0 ≤ a ≤ 0.05; M is Co or Fe; and N is Al, Mn, Fe, Ca, Mg, Ti, Cr, Nb, Mo, W, B, or a mixture thereof provided N may be Fe when M is Co. The mixture is subjected to sintering (1.sup.st step) in air at ≥ 750° C. to form a powder. The powder is subjected to a 2.sup.nd sintering step in O.sub.2 at ≤ 750° C. to form the high nickel lithiated metal oxides.

Disclosed is a doped lithium manganese iron phosphate-based particulate for a cathode of a lithium-ion battery. The particulate includes a composition represented by a formula of M.sub.m-Li.sub.xMn.sub.1-y-zFe.sub.yM′.sub.z(PO.sub.4).sub.n/C, wherein M, M′, x, y, z, m, and n are as defined herein. Also disclosed is a powdery material including the particulate, and a method for preparing the powdery material.

A preparation method of silicon-based composite negative electrode material for a lithium battery includes the following steps: forming steam from a raw material A containing Si and a reducing substance raw material B capable of reacting to generate a silicate under a vacuum heating condition, condensing and depositing in a deposition system after a reaction, and then carrying out carbon coating to obtain the silicon-based composite material. A certain amount of alloy is added into the raw material B, so that a proportion of a crystal region in the silicon-based composite material can be reduced, and the initial coulombic efficiency and the cycling stability of the negative electrode material are further improved.

A molybdenum sulfide powder according to the invention contains molybdenum disulfide having a 3R crystal structure. A heavy-metal adsorbent according to the invention contains molybdenum sulfide particles, and the molybdenum sulfide particles have a median diameter Dso of 10 nm to 1,000 nm obtained by a dynamic light scattering type particle diameter distribution measuring device. A photothermal conversion material according to the invention contains a material containing molybdenum sulfide particles and generates heat by absorbing light energy.

A negative electrode material for a secondary battery including: a matrix including silicon (Si), one or more doping elements (D) selected from the group consisting of alkali metals, alkaline earth metals, and post transition metals, and oxygen (O), based on an element component; and silicon nanoparticles dispersed and embedded in the matrix, wherein the negative electrode material has composition uniformity, and a ratio (A1/A2) between an area of a first peak (A1) and an area of a second peak (A2) satisfying 0.8 to 6, a diffraction angle 2θ being positioned in a range of 10° to 27.4° in the first peak and being positioned in a range of 28±0.5° in the second peak, in an X-ray diffraction pattern using a CuKα ray.