양극 활물질 전구체(NCA)로부터 탄산리튬, 니켈 및 코발트 회수 연구

Abstract

In recent years, lithium-ion batteries have been used as a main energy source for hybrid mobile phones as well as portable mobile power sources such as smart phones and netbooks due to their high output and high energy characteristics. LCO (LiCoO2), which is a layered structure with a stable capacity, has been widely used as a cathode material for lithium ion battery cells, but its price is unstable due to low capacity characteristics, environmental pollution and cobalt resource constraints. Therefore, NCA (LiNiCoAlO2) anode materials came up as an alternative for solving problems such as high cost and low capacity characteristics of LCO (LiCoO2). NCA (LiNiCoAlO2) has recently been in full swing for the electric vehicle battery market, and the demand for used output batteries has increased. Naturally, the demand for NCA, which is a middle- and high-output active material, has also increased. Studies on recycling of existing cathode active materials include leaching into hydrochloric acid (HCl) and nitric acid (HNO3), and recycling of these waste lithium secondary batteries selectively concentrates only electrode active materials for crushing, magnetic separation, classification, etc. After concentration, there is a method using sulfuric acid leaching method using hydrogen peroxide as a reducing agent, and treatment with mountain solution to recover lithium salt and cobalt salt. In the case of using organic acids, the study on the separation of valuable metals by citric acid (C6H8H8E8) and oxygen acid (C2H2SO4) was conducted. The use of such a wet process has the risk of causing costly processing and environmental problems of the byproducts generated during the process, so it is necessary to develop an environmentally friendly process. As a result, in this study, Carbonation through CO2 thermal reaction, water leaching, and CO gas thermal reaction were performed instead of the conventional wet processing. A method of separating and recovering Li2CO3, Co, and Ni from NCA (LiNiCoAlO2), a cathode active material of spent lithium ion batteries, was studied through an environmentally friendly and simple process. It is expected that it will contribute to localization of raw materials when applied to industry by environmentally friendly and simple metal recovery method.