Abstract In a recycling scheme of spent lithium ion batteries, a co-precipitation process for the re-synthesis of precursor is essentialafter the leaching of lithium ion battery scraps. In this study, the effect of ammonia as impurity during the co-precipitation pro-cess was investigated in order to re-synthesize a precursor of Ni-rich cathode active material Ni 0.6 Co 0.2 Mn 0.2 O 2 (NCM 622). Asammonia concentration increases from 1 M (the optimum condition for synthesis of the precursors based on 2 M of metal saltsolution) to 4 M, the composition of obtained precursors deviates from the designed composition, most notably for Ni. The Nico-precipitation efficiency gradually decreases from 100% to 87% when the concentration of ammonia solution increases from1 M to 4 M. Meanwhile, the morphological properties of the obtained precursors such as sphericity, homogeneity and size dis-tribution of particles were also investigated.Key words : recycling, lithium ion battery, NCM, ammonia, co-precipitation · Received : June 5, 2015 · 1st Revised : July 1, 2015 · 2nd Revised : October 1, 2015 · Accepted : October 19, 2015Corresponding Author : Kyungjung Kwon (E-mail : kjkwon@sejong.ac.kr)Department of Energy & Mineral Resources Engineering, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul 05006, KoreaⓒThe Korean Institute of Resources Recycling. All rights reserved. This is an open-access article distributed under the termsof the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permitsunrestricted non-commercial use, distribution and reproduction in any medium, provided the original work is properly cited.