Selective Recovery of Lithium from Cathode Materials of Spent Lithium Ion Battery

Abstract

Selective recovery oflithium from four kinds of cathode materials, manganesetype, cobalt-type, nickel-type, and ternary-type, of spent lithium ion battery was investigated. In all cathode materials, leaching of lithium was improved by adding sodium persulfate (Na2S20 8) as an oxidant in the leaching solution, while the leaching of other metal ions (manganese, cobalt, and nickel) was significantly suppressed. Optimum leaching conditions, such as pH, temperature, amount of Na2S20 8 , and solid/liquid ratio, for the selective leaching of lithium were determined for all cathode materials. Recovery of lithium from the leachate as lithium carbonate (Li2C03 ) was then successfully achieved by adding sodium carbonate (Na2C03) to the leachate. Optimum recovery conditions, such as pH, temperature, and amount of Na2C03 , for the recovery of lithium as Li2C03 were determined for all cases. Purification of Li2C03 was achieved by lixiviation in all systems, with purities of the Li2C03 higher than 99.4%, which is almost satisfactory for the battery-grade purity of lithium.