US 12,407,035 B2Granted

Method for recovering active metal of lithium secondary battery

AssigneeSK Innovation Co., Ltd.

InventorsSuk Joon Hong, Hyeon Bae Ha, Ji Min Kim, Min Ji Sung, Sung Real Son

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Abstract

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.

Claims10

Dependent claims

A method for recovering an active metal of a lithium secondary battery, the method comprising:

preparing a waste cathode active material mixture from a cathode of a lithium secondary battery;
sequentially and continuously performing 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 to convert the cathode active material mixture into a preliminary precursor mixture;
and recovering a lithium precursor from the preliminary precursor mixture, wherein the first reductive reaction gas and the second reductive reaction gas comprise hydrogen, and the hydrogen concentration of the first reductive reaction gas is in a range from 5 to 15 volume % and the hydrogen concentration of the second reductive reaction gas is 20 volume % or more hydrogen.

Dependencies are inferred from the claim text.