A method for preparing ternary positive electrode materials by recycling waste ternary lithium batteries

Abstract

The invention provides a method for preparing a ternary positive electrode material by recycling waste ternary lithium batteries, comprising: 1) mixing pretreated waste positive electrode powder of nickel cobalt lithium manganese oxide and sulfate, and roasting to obtain a roasted product; 2) Soak the roasted product in water to obtain water leaching liquid and water leaching slag; the water leaching liquid contains lithium salt; 3) react the water leaching slag with acid solution and hydrogen peroxide to obtain a nickel-cobalt-manganese leaching liquid; 4) extract the nickel-cobalt-manganese Extraction of cobalt, manganese, nickel after impurity removal of the leachate, saponification and stripping of the obtained organic phase to obtain cobalt sulfate, manganese sulfate and nickel sulfate solution; 5) the nickel sulfate, cobalt sulfate and manganese sulfate solution with sodium hydroxide Co-precipitate the solution and ammonia water, mix the obtained precursor with lithium carbonate, sinter, and sieve iron to obtain a ternary positive electrode material. The method provided by the invention firstly extracts lithium, reduces the influence of lithium element on the subsequent extraction of nickel, cobalt and manganese, reduces the impurity content in the ternary positive electrode material, greatly improves the recovery rate of nickel, cobalt and manganese, and can also increase the recovery rate of lithium.

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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