Method for recycling valuable components in waste ternary lithium ion battery through high-temperature in-situ heat treatment

Abstract

The invention discloses a method for recycling valuable components in a waste ternary lithium ion battery through high-temperature in-situ heat treatment. The method comprises the steps of carrying out the in-situ thermal reduction on the nickel-cobalt-manganese high-valence elements in an electrode material by utilizing the organic substances, such as a positive and negative electrode material surface binder, carbon black, etc., reducing the nickel and cobalt to be in an elemental form, and reducing manganese to be low-valence oxide manganese monoxide; recycling the lithium element by adopting a water immersion method, and drying the residual materials, and then separating the ferromagnetic nickel-cobalt elementary substances, diamagnetic graphite and non-magnetic manganese monoxide through a magnetic separator with high magnetic flux; selecting a magnetic separator with low magnetic flux to separate and recover nickel and cobalt. Compared with a traditional ore pulp electrolysis process and other hydrometallurgy processes, a reducing agent does not need to be added, the interference of impurity elements in a recovery system is reduced, and finally the recovery rates of nickel, cobalt, manganese and negative electrode graphite are all larger than 98%. According to the process, the process of recycling the valuable components in the waste ternary lithium ion battery electrode material is simplified, the cost is reduced, and the method is a good choice for industrial application.

Description

technical field [0001] The invention relates to the technical field of resource recycling of waste ternary lithium-ion batteries, in particular to a method for recovering valuable components in positive and negative electrode materials of waste ternary lithium-ion batteries through high-temperature in-situ heat treatment. Background technique [0002] Ternary lithium-ion batteries are widely used in new energy vehicles due to their high energy density, long cycle life, and low self-discharge rate. However, due to technical limitations, the life of lithium-ion batteries is limited. At present, the service life of a battery pack is generally 1-3 years. Data show that by 2020, 500,000 tons of waste lithium-ion batteries will be produced, equivalent to 2.5 billion batteries. On the one hand, lithium-ion batteries contain a large amount of valuable metals, such as Li, Ni, Co, Mn, etc., which have high recycling value. On the other hand, toxic heavy metal substances and corrosive...

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Problems solved by technology

[0003] Aiming at the recovery of valuable components in waste ternary lithium-ion batteries, many methods and processes have been proposed in the currently applied patents (application numbers: CN201910930414.7, CN201710309061.X, CN201810928779.1, etc.), mainly divided into physical The physical method mainly includes crushing, screening, etc., and the chemical method mainly includes hydrometallurgy and pyrometallurgy. Regardless of the method, there are the following problems: First, because the surface of the positive and negative electrodes is During the battery manufacturing process, a binder (PVDF) will be added to stick the electrode material on the current collector, because the presence of the binder makes the surface of the electrode material wrapped with an organic film, on the one hand, it changes the surface properties of the positive and negative materials, It is impossible to separate the positive and negative materials by conventional methods. On the other hand, the coating of the organic film also makes the subsequent hydrometallurgical process impossible; second, even after the removal of the organic film, due to the Elements exist in the form of high valence state, have strong chemical bonds, and the direct leaching efficiency is low, so it is necessary to add a reducing agent in the pretreatment process or hydrometallurgy process to reduce the high valence state elements and increase the leaching rate, so the cost is high. Complex process

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