With the increasing market share of new energy vehicles, as one of the core components of new energy vehicles, the number of waste power batteries will also increase. Waste power batteries contain a lot of valuable metals, among which the contents of nickel, cobalt, manganese and Li Can reach 5~ 12%, 5~20%, 7~ 10% and 2~5% respectively. The recycling of waste power batteries can not only improve the self-sufficiency rate of raw materials, but also reduce the impact on the environment.
Nickel, cobalt and manganese are recovered from the cathode materials of waste lithium batteries, most of which are enriched in acid leaching solution, and then impurities are removed by chemical precipitation, replacement, ion exchange and extraction, and the obtained impurity removal solution is separated and purified to prepare various high-purity nickel, cobalt and manganese salts. For example, China patent cn 1 12646974a discloses a method for recovering valuable metals from waste ternary lithium battery cathode materials. The method comprises the following steps: firstly, performing acid leaching on the cathode material to obtain an acid leaching solution; then sequentially adding sodium carbonate and sodium fluoride to remove iron, aluminum, calcium, magnesium and lithium; and finally extracting cobalt, manganese and nickel with p507 and p204 respectively. For another example, China patent cn 1 10527835n discloses a method for recycling all components of waste ternary lithium battery soft packaging, which uses sodium hydroxide solution to adjust the ph value of acid leaching solution to 6.5.
0. 1, impurity removal of fe/al is realized, and then the solution after impurity removal is directly precipitated to prepare the precursor. For another example, China patent CN112048615A discloses a method for recovering sulfate from waste ternary batteries. In this method, aluminum foil and anode powder materials are separated from waste ternary lithium batteries by roasting, and then the anode powder materials are acid-leached, and copper is extracted and removed; fe/al is neutralized with sodium carbonate or sodium hydroxide, and nickel, cobalt and manganese sulfate are recovered by extraction and separation.
However, the above methods have the following problems: (1) The impurity removal or separation of nickel, cobalt and manganese is realized by extraction, which has complicated process and high cost; (2) When using neutralization precipitation method to remove impurities, the neutralizer used is sodium hydroxide or sodium carbonate, and ni/co/mn will suffer serious losses due to the formation of local overbased or insoluble carbonate; (3) Most of the prepared products are high-purity ni/co/mn salts, which are mixed during the preparation of precursors, resulting in the waste of separation process and the increase of cost.