Abstract: A cobalt-coated lithium manganese complex oxide is disclosed. This provides a particularly high discharge capacity which is useful for the improvement of cycle characteristics of a secondary battery as an active material of a positive electrode for a secondary battery with a nonaqueous electrolyte.

Abstract: The present invention relates to cobalt oxide particles useful as a precursor of a cathode active material for a non-aqueous electrolyte secondary cell which is capable of showing a stable crystal structure by insertion reaction therein, and producing a non-aqueous electrolyte secondary cell having a high safety and especially a high heat stability, a process for producing the cobalt oxide particles, a cathode active material for a non-aqueous electrolyte secondary cell using the cobalt oxide particles, a process for producing the cathode active material, and a non-aqueous electrolyte secondary cell using the cathode active material.

Abstract: A manganese oxide which has a calcium or/and magnesium content of 0.01 to 2.50 mol % based on the moles of manganese, a lithuim manganese complex oxide using the manganese oxide, and a cobalt-coated lithuim manganese complex oxide are disclosed. These provide a particularly high discharge capacity and are useful for the improvement of cycle characteristics of a secondary battery as an active material of a positive electrode for a secondary battery with a nonaqueous electrolyte.

Abstract: A manganese oxide which has a calcium or/and magnesium content of 0.01 to 2.50 mol % based on the moles of manganese, a lithuim manganese complex oxide using the manganese oxide, and a cobalt-coated lithuim manganese complex oxide are disclosed. These provide a particularly high discharge capacity and are useful for the improvement of cycle characteristics of a secondary battery as an active material of a positive electrode for a secondary battery with a nonaqueous electrolyte.

Abstract: A manganese oxide which has a calcium or/and magnesium content of 0.01 to 2.50 mol % based on the moles of manganese, a lithium manganese complex oxide using the manganese oxide, and a cobalt-coated lithium manganese complex oxide are disclosed. These provide a particularly high discharge capacity and are useful for the improvement of cycle characteristics of a secondary battery as an active material of a positive electrode for a secondary battery with a nonaqueous electrolyte.

Abstract: A cathode active material for a non-aqueous electrolyte secondary cell of the present invention, has a c-axis length of lattice constant of 14.080 to 14.160 Å, an average particle size of 0.1 to 5.

Abstract: A process for producing lithium-cobalt oxide, comprises: mixing cobalt oxide having a BET specific surface area of 30 to 200 m.sup.2 /g or an average particle size of not more than 0.1 .mu.m, with a lithium compound; and calcining the obtained mixture at a temperature of 500 to 850.degree. C. Such a process for producing lithium-cobalt oxide particles is useful especially as a cathode active substance for lithium ion batteries, which particles can be produced by calcination in a short time, and have a narrow particle size distribution and a uniform small particle size.

Abstract: The disclosure describes a process for producing Co-coated acicular magnetite particles each comprising:acicular magnetite particle as the core particle;a lower coating layer of Co-containing spinel ferrite having a spinel structure, which is formed on the surface of said acicular magnetite particle; andan upper coating layer of Co- and Mg-containing spinel ferrite having a spinel structure, which is formed on said lower coating layer.

Abstract: Acicular magnetic iron oxide particles comprise:acicular magnetite particles having 10 to 24% by weight of ferrous as core particles;a magnetite coating which is formed on the surfaces of said acicular magnetite particles by epitaxial growth and which has maghemite at least in a part of the surface of said magnetite coating; anda cobalt-containing oxide layer which is formed on said magnetite coating and which contains cobalt of 1.5 to 2.5 wt % based on the total weight of said acicular magnetic iron oxide particles.

Abstract: Co-coated acicular magnetite particles each comprising:acicular magnetite particle as the core particle;a lower coating layer of Co-containing spinel ferrite having a spinel structure, which is formed on the surface of said acicular magnetite particle; andan upper coating layer of Co- and Mg-containing spinel ferrite having a spinel structure, which is formed on said lower coating layer.

Abstract: Disclosed herein are a process for producing acicular goethite particles comprising the steps of: blowing an oxygen-containing gas into a ferrous salt reaction solution containing colloidal ferrous hydroxide or iron-containing colloidal precipitates which is obtained by reacting an aqueous ferrous salt solution with less than one equivalent of an aqueous alkali hydroxide solution and/or an aqueous alkali carbonate solution based on Fe.sup.2 + in said aqueous ferrous salt solution so as to oxidize said colloidal ferrous hydroxide or iron-containing colloidal precipitates and to produce acicular goethite nucleus particles, adding to the resultant aqueous ferrous salt reaction solution containing said acicular goethite nucleus particles not less than one equivalent of an aqueous alkali carbonate solution based on Fe.sup.

Abstract: Disclosed herein are poreless, non-sintered plate-like magnetite particles having an average particle diameter of more than 0.5 .mu.m and not more than 2.0 .mu.m, and a BET specific surface area of not more than 6.0 m.sup.2 /g, and poreless, non-sintered plate-like maghemite particles having an average particle diameter of more than 0.5 .mu.m and not more than 2.0 .mu.m, and a BET specific surface area of not more than 6.0 m.sup.2 /g.

Abstract: Plate-like magnetite particles, plate-like maghemite particles and the processes for producing these particles are herein disclosed. The plate-like magnetite particles and the plate-like maghemite particles provided according to the present invention are fine plate-like particles which are poreless and non-sintered as the plate-like magnetite particles are produced directly from an aqueous solution and these plate-like magnetite particles are oxidized by heating to produce the plate-like maghemite particles. Therefore, these particles can be filled to a high density in a vehicle or resin, have good dispersibility and orientability and are also high in a degree of particle contact, so that they are suited for use as electromagnetic wave absorbing and shielding material, magnetic material for magnetic recording, black or brown pigment for paints and colorant for rubber and plastic products.