In a method for recovering an active metal of a lithium secondary battery, a cathode active material mixture is prepared from a cathode of a lithium secondary battery. A first reductive process using a first reductive reaction gas and a second reductive process using a second reductive reaction gas that has a higher reaction source concentration than that of the first reductive reaction gas are performed sequentially and continuously to convert the cathode active material mixture into a preliminary precursor mixture. A lithium precursor is recovered from the preliminary precursor mixture. A lithium recovery ratio may be increased by a stepwise reduction while preventing an increase of heating value.

One aspect of the present invention is a positive active material that contains an oxide containing lithium, a transition metal element and a typical element, and having an antifluorite crystal structure, in which the transition metal element is cobalt, iron, copper, manganese, nickel, chromium, or a combination thereof, the typical element is a group 13 element, a group 14 element, phosphorus, antimony, bismuth, tellurium or a combination thereof, and a molar ratio of a content of the typical element to a total content of the transition metal element and the typical element in the oxide is more than 0.05 and 0.5 or less.

One aspect of the present invention is a positive active material that contains an oxide containing lithium, a transition metal element and a typical element, and having an antifluorite crystal structure, in which the transition metal element is cobalt, iron, copper, manganese, nickel, chromium, or a combination thereof, the typical element is a group 13 element, a group 14 element, phosphorus, antimony, bismuth, tellurium or a combination thereof, and a molar ratio of a content of the typical element to a total content of the transition metal element and the typical element in the oxide is more than 0.05 and 0.5 or less.

A method for separating a transition metal from a waste positive electrode material includes step 1 of preparing a waste positive electrode material represented by Formula 1, step 2 of heat treating the waste positive electrode material in an inert gas atmosphere or an oxygen atmosphere to phase separate the waste positive electrode material into a lithium oxide and a metal oxide, step 3 of cooling an obtained product of step 2 to room temperature in an inert atmosphere, and step 4 of mixing a cooled product cooled to room temperature in step 3 with distilled water, and then filtering the mixture to leach a transition metal.

A method for separating a transition metal from a waste positive electrode material includes step 1 of preparing a waste positive electrode material represented by Formula 1, step 2 of heat treating the waste positive electrode material in an inert gas atmosphere or an oxygen atmosphere to phase separate the waste positive electrode material into a lithium oxide and a metal oxide, step 3 of cooling an obtained product of step 2 to room temperature in an inert atmosphere, and step 4 of mixing a cooled product cooled to room temperature in step 3 with distilled water, and then filtering the mixture to leach a transition metal.

This document describes processes for preparing ceramics, especially lithium-based ceramics. The ceramics produced by this process and their use in electrochemical applications are also described as well as electrode materials, electrodes, electrolyte compositions, and electrochemical cells comprising them.

A reducing agent for use in production of a product gas containing carbon monoxide, the reducing agent being brought into contact with a raw material gas containing carbon dioxide to reduce the carbon dioxide to produce the product gas; the reducing agent containing an oxygen carrier having oxygen ionic conductivity, and a basic oxide supported on the oxygen carrier. In addition, the basic oxide preferably contains at least one selected from the group consisting of lithium (Li), sodium (Na), potassium (K), magnesium (Mg), manganese (Mn), cobalt (Co), strontium (Sr), and rubidium (Rb). The reducing agent has a high conversion efficiency of carbon dioxide to carbon monoxide, and can be used, for example, in a chemical looping method, and a method for producing a gas using such a reducing agent.

A Li ion conductor having a composition different from a conventional composition is provided. The Li ion conductor contains at least one selected from a group Q consisting of Ga, V, and Al, Li, La and O. A part of an Li site is optionally substituted with a metal element D, a part of an La site is optionally substituted with a metal element E, and parts of Ga, V and Al sites are optionally substituted with a metal element J. A mole ratio of an amount of Li to a total amount of La, the element E, Ga, V, Al, and the element J is not lower than 8.1/5 and not higher than 9.5/5. A mole ratio of a total amount of Ga, V, and Al to a total amount of La and the element E is not lower than 1.1/3 and not higher than 2/3.

A Li ion conductor having a composition different from a conventional composition is provided. The Li ion conductor contains at least one selected from a group Q consisting of Ga, V, and Al, Li, La and O. A part of an Li site is optionally substituted with a metal element D, a part of an La site is optionally substituted with a metal element E, and parts of Ga, V and Al sites are optionally substituted with a metal element J. A mole ratio of an amount of Li to a total amount of La, the element E, Ga, V, Al, and the element J is not lower than 8.1/5 and not higher than 9.5/5. A mole ratio of a total amount of Ga, V, and Al to a total amount of La and the element E is not lower than 1.1/3 and not higher than 2/3.

This invention relates to a method for the preparation of lithium carbonate from lithium chloride containing brines. The method can include a silica removal step, capturing lithium chloride, recovering lithium chloride, supplying lithium chloride to an electrochemical cell and producing lithium hydroxide, contacting the lithium hydroxide with carbon dioxide to produce lithium carbonate.