Acid Leaching Process of Waste Power Lithium Ion Battery

Abstract

The power lithium ion battery has been widely used for its excellent performance, with the waste batteries increased yearly and causing environmental pollution and resource waste. The problem must be solved immediately. In this paper, through the “alkaline separation-roasting-acid leaching” process, spent lithium ion battery anode is handled so that to achieve the extraction of valuable metals in the anode. The results show positive active material can separate from the aluminum foil by means of the using of NaOH solution. Under the process of 700 ℃ high-temperature roasting for 2 h, active substances Li (NixCo1-x) O2 transform into NiO, CoO, etc., and it is conducive to subsequent acid leaching. After roasting, the acid leaching of active substance is conducted through respectively using hydrochloric acid and sulfuric acid. The leaching rate of Li, Ni, Co are 99.9, 99.5, 99.2% under the optimum conditions in hydrochloric acid system respectively: the concentration of the acid 2 mol/L, the ratio of solid-liquid 60 mg/ml, leaching temperature 90 ℃ and leaching time 50 min. In sulfuric acid system, the leaching rate of Li, Ni, Co are all closer to 100% under the optimum conditions: the concentration of the acid 2 mol/L, the S/L 75 mg/ml, leaching temperature 85 ℃ leaching time 50 min and volume ratio of hydrogen peroxide is 5%. Through the fitting calculation, acid leaching is applied to the nuclear reaction model and leaching of lithium nickel and cobalt are controlled by chemical reaction. Two kinds of acid system all have good results for metal extraction from waste lithium ion battery cathode material. Considering recycling cost and environmental impact, sulfuric acid system is better.