Method for assisting recovery of lithium and cobalt in waste electrode material through microwave roasting

Abstract

The invention discloses a method for assisting recovery of lithium and cobalt in a waste electrode material through microwave roasting. The method comprises the following steps of, step (1), crushingand screening a positive plate to obtain electrode material powder; step (2), putting the obtained positive electrode active material into a microwave tube furnace filled with inert protective gas forroasting, and collecting the roasted solid-phase product; step (3), mixing the solid-phase product with excess organic acid, preparing an acid leaching solution, and recovering cobalt salt precipitate; and step (4), adding any one of phosphoric acid, phosphate or carbonate into the leaching solution, and recovering the precipitate of the lithium. According to the method, the electrode material ispre-reduced in a microwave roasting mode, a binder PVDF plays a role of a reducing agent, the acid leaching characteristic of the lithium and the cobalt in the positive electrode material is optimized, the energy consumption and the gent consumption in the recovery process are reduced, and the pretreatment process is simplified; and the method has the advantages of high efficiency, low energy consumption, environmental friendliness and the like.

Description

technical field [0001] The invention belongs to the field of recycling waste lithium ion batteries, and in particular relates to a method for recovering lithium and cobalt in waste electrode materials assisted by microwave roasting. Background technique [0002] Lithium-ion battery, as an efficient and environmentally friendly electric energy carrier, has been widely used in energy storage devices, consumer electronics, and power batteries due to its many advantages such as high energy density, long cycle life, and no memory effect. With the vigorous development of my country's consumer electronics and new energy automobile industries, the demand and output of lithium-ion batteries continue to rise. According to statistics, the national output of lithium batteries reached 12.1 billion in 2018, a year-on-year increase of 22.86%. Generally, lithium-ion batteries are prone to problems such as battery level expansion and capacitance drop after 1-3 years of use, and enter the sc...

AI Technical Summary

Problems solved by technology

First of all, elements such as cobalt and manganese in the electrode material are difficult to dissolve in the solution due to their high valence, resulting in low wet leaching efficiency.

In addition, due to the external heating leaching method adopted in the traditional wet recovery process, the chemical reaction only occurs on the surface of the solid particles, resulting in hindered leaching reaction, slow rate, and difficulty in heat transfer

And the organic binder PVDF contained in the electrode material covers the surface, affecting its acid leaching behavior

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