Copper extraction from the ammonia leach liquor of spent lithium ion batteries for regenerating LiNi0.5Co0.5O2 by co-precipitation

摘要

The traditional process of separating valuable metals from spent lithium ion battery (LIB) leaching solutions in which Cu, Ni, Co and Li coexist is cumbersome and costly. LIX984 is commonly used to extract copper from acidic environments. In this work, we develop a novel process using LIX984 as extractant to remove the Cu from the high pH ammonia leaching solution of spent LIB batteries. Then, Li, Ni, and Co is recovered from the aqueous phase to regenerate the LiNi0.5Co0.5O2 cathode materials using a co-precipitation method. Up to 97.85% of Cu and 2.89% of Ni are extracted by LIX984, while almost all the Li and Co remained in the liquid phase under the following optimum conditions: organic/aqueous phase ratio of 1, 15% LIX984, and 25 degrees C reaction for 10 min. A H2SO4 solution of 1.5 M or higher could completely strip the extracted Cu from the organic phase. The regenerated cathode material LiNi0.5Co0.5O2 appeared as spherical particles with no impurities and demonstrated excellent electrochemical performance. The discharge specific capacity remained at 145.8 mAh center dot g(-1) after 100 cycles. Therefore, this process may be a potential alternative technology to simplifying the spent LIB recycling process.