Methods for leaching valuable metals from waste lithium ion ternary positive electrode material and preparing ternary positive electrode material precursor

Abstract

The invention discloses a method for leaching valuable metals from a waste lithium ion ternary positive electrode material. The method comprises the following steps: carrying out ball milling on an active substance separated from the waste lithium ion battery positive electrode material to obtain powder; wetting the powder with water to obtain a wet material; mixing the wet material with concentrated sulfuric acid; roasting at low temperature to obtain a roasted material; and carrying out water leaching on the roasted material, and carrying out solid-liquid separation to obtain carbon and a metal leachate. According to the method for leaching the valuable metal, efficient leaching of the metal is achieved under the condition that no reducing agent or additive exists, and energy consumptionis reduced. The invention further discloses a method for adjusting the molar ratio of nickel to cobalt to manganese in the leachate, then adding the urea, mixing with the ethylene glycol and carryingout a hydrothermal reaction to prepare a ternary positive electrode material precursor, so that separation of different metals is avoided, valuable metals are effectively recycled, the process flow is shortened, the operation is simple, industrial production is facilitated, and the prepared ternary positive electrode material precursor has excellent electrochemical performance.

Description

technical field [0001] The invention belongs to a resource recovery method of waste batteries, in particular to a method for leaching valuable metals from waste lithium ion ternary positive electrode materials and preparing a precursor of ternary positive electrode materials. Background technique [0002] Since 1990, ternary lithium-ion batteries have the advantages of high operating voltage, high energy density, no memory effect, light weight, small size, low self-discharge rate, long cycle life, and wide operating temperature range. It has been widely used in portable electronic devices and electric vehicles. As demand continues to rise, it is estimated that by 2030, the worldwide processing capacity of waste lithium ions will exceed 11 million tons, and its processing capacity will usher in explosive growth. Lithium-ion batteries contain a large amount of valuable metals, and the metal content in some lithium-ion batteries is even higher than that of natural ores, which ...

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Problems solved by technology

In order to ensure the full recovery of valuable metals, excessive sulfuric acid and additional reducing agents need to be added in the recovery process, which has a strong corrosion effect on production equipment, and increases the difficulty of wastewater treatment, increasing economic costs and environmental pressure

[0005] It is also disclosed in the technical literature that after the electrode material is crushed, it is mixed with concentrated sulfuric acid, etc., and the secondary heat treatment is carried out at a high temperature (above 350°C) in the electric furnace, so that the metals such as cobalt, copper and lithium in the waste lithium ion battery Transform into sulfates that are easily soluble in water. However, the boiling point of concentrated sulfuric acid is 338 ° C. If the reaction is carried out at a temperature higher than the boiling point, the sulfuric acid will quickly volatilize and produce SO 3 Gas, gas-solid reaction occurs with the ternary positive electrode material, and the ternary material will bubble a lot under the support of the gas. Sodium sulfate (potassium sulfate) needs to be added to adjust so that the slurry is not easy to overflow. This process consumes a lot of energy and is harmful to the High equipment requirements

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