Method for preparing ternary positive electrode material through recovering waste ternary lithium battery

Abstract

The invention provides a method for preparing a ternary positive electrode material through recovering a waste ternary lithium battery. The method comprises the following steps of 1) mixing pretreatednickel cobalt lithium manganate waste positive electrode powder with sulfate, and roasting to obtain a roasted product; 2) immersing the roasted product in water to obtain water immersion liquid andwater immersion slag; wherein the water immersion liquid contains lithium salt; 3) reacting the water immersion slag with an acid solution and hydrogen peroxide to obtain a nickel-cobalt-manganese leaching solution; 4) removing impurities from the nickel-cobalt-manganese leaching solution, then extracting cobalt, manganese and nickel, and saponifying and reversely extracting obtained organic phaseto obtain a nickel sulfate solution, a cobalt sulfate solution and a manganese sulfate solution; and 5) co-precipitating the nickel sulfate solution, the cobalt sulfate solution and the manganese sulfate solution with a sodium hydroxide solution and ammonia water, mixing obtained precursor with lithium carbonate, sintering, and screening iron to obtain the ternary positive electrode material. According to the method, lithium is extracted firstly, so that the influence of a lithium element on subsequent nickel-cobalt-manganese extraction is reduced, the impurity content in the ternary positiveelectrode material is reduced, and the recovery rate of nickel-cobalt-manganese is greatly improved; and meanwhile the recovery rate of the lithium can be improved.

Description

technical field [0001] The invention belongs to the technical field of recycling waste lithium batteries, and in particular relates to a method for preparing ternary cathode materials by recycling waste ternary lithium batteries. Background technique [0002] In the past 10 years, China's electric vehicle industry has achieved rapid development. At the same time, the earliest electric vehicles to enter the market have now entered the stage of battery decommissioning, and the number of decommissioned batteries will increase sharply in the next few years. According to market research forecasts, by 2020, the amount of scrapped lithium batteries for vehicles in my country will reach 32GWh, and the quality of scrapped batteries will reach about 500,000 tons; by 2030, the amount of scrapped lithium batteries for vehicles will reach 300GWh, and the amount of scrapped lithium batteries will reach about 3 million tons. Lithium batteries are mainly divided into lithium iron phosphate...

AI Technical Summary

Problems solved by technology

[0003] The ternary lithium battery contains metal elements such as cobalt and nickel. If it is not recycled, it will not only cause a great waste of resources, but also cause pollution to the ecological environment, thereby limiting the sustainable development of the new energy automobile industry.

[0005] This all-wet recovery method has the following problems: (1) after the manganese, nickel, cobalt, and lithium in the positive electrode material are reduced and leached together, the lithium element in the solution will have an impact on the recovery of nickel and cobalt, resulting in relatively high impurity content in the final precursor product. High, thus affecting the electrochemical performance of the ternary cathode material

(2) After extraction and separation of the leaching solution, a small part of lithium is entrained or extracted by the miscible phase, and the content of lithium in the leaching solution is low, resulting in high subsequent recovery costs and low recovery rates

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