Method for leaching metals in anode material of waste lithium ion battery

Abstract

The invention relates to a method for leaching metals in an anode material of a waste lithium ion battery. The method for leaching the metals in the anode material of the waste lithium ion battery comprises the steps that anode active substances are obtained after the waste lithium ion battery is pretreated, then the anode active substances are made to react with an ammonium salt solution containing a reducing agent, solid-liquid separation is conducted after the reaction, and thus, leachate and filter residues are obtained. According to the method, the process is simple, the metal leaching rate is high, and the metal selectivity is high; by controlling the type and quantity of the reducing agent used in the leaching process, selective leaching of the metals can be achieved, for instance,when the anode material contains metals such as Li, Co and Mn, the reducing agent is ammonium sulfite, the leaching rate of Mn is 90% when the concentration of the reducing agent is 0.75 mol / L, and the leaching rate of Mn is 4% when the concentration of the reducing agent is 1.5 mol / L; the impurity content of the leachate is low, so that the cost for the subsequent impurity removal procedure is low; and the leaching process is conducted in a high-pressure kettle, emission of poisonous gas is avoided in the operation process, and the operation environment is good.

Description

technical field [0001] The invention relates to the field of comprehensive recovery and utilization of waste lithium ion batteries, and more specifically, relates to a method for leaching metals in positive electrode materials of waste lithium ion batteries. Background technique [0002] Lithium-ion batteries have been widely used in mobile electronic devices, power vehicles, energy storage and other fields due to their excellent characteristics such as high energy density, long cycle life, low self-discharge rate, low pollution, and no memory effect. According to statistics, the output of lithium-ion batteries in China reached 5.6 billion in 2015. However, the service life of lithium batteries is generally 3-6 years, and the number of waste lithium-ion batteries due to end of life or other reasons is increasing. The cathode materials currently used in commercial lithium-ion batteries are binary or ternary materials composed of lithium cobalt oxide, lithium iron phosphate, l...

AI Technical Summary

Problems solved by technology

[0004] In view of the above existing technologies, the pyrotechnic process equipment requires high requirements, and the purity of the alloy is low. The subsequent hydrometallurgical process still needs a series of purification and impurity removal steps

The selectivity of acid leaching to metals in the wet process is low, resulting in high impurity content in the leaching solution, the subsequent impurity removal process is cumbersome, and the acid gas and wastewater generated are difficult to treat; the microbial culture used in bioleaching is complicated, and the leaching treatment cycle is long. Alkaline leaching, especially ammonia leaching, has high selectivity to metals, but the leaching rate of valuable metals such as Co and Ni is low, and there are problems such as easy volatilization of ammonia water and poor operating environment in the leaching process

The repair and regeneration of positive electrode materials generally require high purity raw materials and less impurities, and are mostly used in the recycling of unqualified products or leftovers on the battery production line. This process needs further improvement for the mixed types of waste lithium-ion batteries on the market. verify

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