An object of the present invention is to provide an inorganic oxide powder suitable for forming an inorganic oxide porous membrane, which is superior in lithium ion conductivity and has insulation performance, on at least one surface of a positive electrode, a negative electrode and a separator which constitute a lithium ion secondary battery. The present invention relates to an inorganic oxide powder for use in forming an inorganic oxide porous membrane having insulation performance on at least one surface of a positive electrode, a negative electrode and a separator which constitute a lithium ion secondary battery, wherein the powder has 1) an oxide purity of 90% by weight or higher; 2) an average particle diameter of 1 m or less; and 3) an average three-dimensional particle unevenness of 3.0 or higher.

An object of the present invention is to provide an inorganic oxide powder suitable for forming an inorganic oxide porous membrane, which is superior in lithium ion conductivity and has insulation performance, on at least one surface of a positive electrode, a negative electrode and a separator which constitute a lithium ion secondary battery. The present invention relates to an inorganic oxide powder for use in forming an inorganic oxide porous membrane having insulation performance on at least one surface of a positive electrode, a negative electrode and a separator which constitute a lithium ion secondary battery, wherein the powder has 1) an oxide purity of 90% by weight or higher; 2) an average particle diameter of 1 m or less; and 3) an average three-dimensional particle unevenness of 3.0 or higher.

Disclosed herein are acid-base leaching methods and systems. Specifically, the systems and methods can include reacting a feed material comprising at least two metals selected from the group consisting of iron, magnesium, and calcium with a weak acid to produce a first leachate comprising ions of the at least two metals and an insoluble product; reacting the first leachate with a base to produce a first solid product comprising a first metal and a second leachate comprising ions of a second metal different from the first metal; and reacting the second leachate with the base to produce a second solid product comprising the second metal and a third leachate.

Disclosed herein are acid-base leaching methods and systems. Specifically, the systems and methods can include reacting a feed material comprising at least two metals selected from the group consisting of iron, magnesium, and calcium with a weak acid to produce a first leachate comprising ions of the at least two metals and an insoluble product; reacting the first leachate with a base to produce a first solid product comprising a first metal and a second leachate comprising ions of a second metal different from the first metal; and reacting the second leachate with the base to produce a second solid product comprising the second metal and a third leachate.

A method for producing a sheet phase pseudo-boehmite. The method includes: a) putting an organic acid into an aqueous solution in which an aluminum precursor is dispersed; and b) putting a product from the process of a) into a Taylor reactor, wherein a pressure of the Taylor reactor is 1 to 100 bar.

A method for producing a sheet phase pseudo-boehmite. The method includes: a) putting an organic acid into an aqueous solution in which an aluminum precursor is dispersed; and b) putting a product from the process of a) into a Taylor reactor, wherein a pressure of the Taylor reactor is 1 to 100 bar.