The present invention relates to a method of preparing an iron-chromium oxide using an ion-exchange resin. Moreover, the present invention relates to a method of preparing an iron-chromium oxide that can be used as a cathode material for lithium-ion batteries. According to one aspect of the present invention, it has the effect of providing a cathode material for lithium-ion batteries with a high capacitance, while exhibiting a voltage similar to that of a transition-metal oxide (2-4.5 V vs Li.sup.+/Li).

As for a secondary battery using lithium cobalt oxide as a positive electrode active material, the positive electrode active material with which a decrease in battery capacity due to repeated charge and discharge is inhibited is provided. Alternatively, a positive electrode active material particle which hardly deteriorates is provided. The positive electrode active material includes lithium, cobalt, oxygen, magnesium, aluminum, and fluorine and is a crystal represented by a layered rock-salt structure. The space group of the crystal is represented by R−3m. The concentration of fluorine in a surface portion of the crystal is higher than that inside the crystal. The concentration of magnesium in the surface portion of the crystal is higher than that inside the crystal. The atomic ratio of magnesium to aluminum in the surface portion of the crystal is higher than that inside the crystal.

Several variations of synthetic carbon materials are disclosed. The materials can assume a variety of properties, including high electrical conductivity. The materials also can have favorable structural and mechanical properties. They can form gas impenetrable barriers, form insulating structures, and can have unique optical properties.

The invention relates to a process for the preparation of a vanadium-carbon phosphate composite material, a vanadium-carbon phosphate composite material obtained according to the process, and to the uses of the composite material, especially as a precursor for the synthesis of electrochemically-active materials, electrode or active anode material.

A cathode material, containing a crystal with a superlattice structure, is provided. A chemical formula of the crystal is xLi.sub.2MO.sub.3.(1-x)LiNi.sub.aCo.sub.bMn.sub.(1-a-b)O.sub.2, where 0<x≤0.1, 0.8≤a<1, b≤0.1, and M is selected from one or more of Mn, Co, and Ni. A preparation method of the cathode material and a battery or a capacitor containing the cathode material are also provided.

A method according to an embodiment of the present invention is for preparing powdered composite carbide of tungsten and titanium in which tungsten trioxide (WO.sub.3), titanium dioxide (TiO.sub.2) and carbon (C), each being in powdered form are mixed with a reducing agent powder to obtain a reaction mixture in the mixing step, followed by the synthesis step in which the reaction mixture is heated at a temperature of about 600° C. to 1200° C. to obtain the reaction products, and the washing step in which the reaction products are washed with water. The method for preparing tungsten titanium carbide powder is capable of carrying out both reduction and carburizing at a relatively low temperature and affords homogeneity in shape and particle size in the resultant composite carbide.

The sodium ferrite particle powder according to the present invention is characterized in that at least one metal or more selected from the metal group consisting of silicon, aluminum, titanium, manganese, cobalt, nickel, magnesium, copper and zinc is contained in an amount of 0.05 to 20% by weight in terms of the oxide, and the molar ratio of Na/Fe is 0.75 to 1.25.

Provided in the present disclosure are a positive electrode material used for a lithium ion battery. The positive electrode material comprises substrate particles, a first cladding layer that covers the substrate particles, and a second cladding layer that covers the first cladding layer; the substrate particles contain LiNi.sub.xMn.sub.y Co.sub.zM.sub.1-x-y-zO.sub.2; the first cladding layer contains lithium cobalt oxide; and the second cladding layer contains an oxide of a transition metal.

A method for preparing lanthanum carbonate tetrahydrate and a product thereof. The lanthanum carbonate tetrahydrate is prepared by reacting lanthanum oxide and acetic acid with potassium carbonate or potassium bicarbonate or ammonium bicarbonate to prepare lanthanum carbonate octahydrate, and drying the lanthanum carbonate octahydrate. Compared with the lanthanum carbonate tetrahydrate in the prior art, the prepared lanthanum carbonate tetrahydrate has a characteristic spectral peak on a terahertz spectrum, and has excellent dissociation and dissolution characteristics of lanthanum ions.

A talc particulate, a polymer composition comprising said talc particulate, methods of making said talc particulate and said polymer composition, and the various uses of said talc particulate.