Method and system for recycling positive poles from waste lithium batteries and carrying out regeneration and repair

Abstract

The invention discloses a method and system for recycling positive poles from waste lithium batteries and carrying out regeneration and repair. The method comprises the steps of recycling an electrolyte in a waste ternary lithium battery; removing a binder in the obtained positive and negative pole pieces, separating out the positive pole piece through cold quenching, magnetic separation and screening, then carrying out roasting treatment to obtain positive pole powder; and grinding and sintering a mixture containing the positive pole powder, lithium salt and a coating raw material to obtain arepaired composite cathode material. According to the invention, the components of the lithium battery are classified and recycled, priority is given to the recycling of the electrolyte, the anode and cathode materials are accurately disassembled and separated, the technological conditions are strictly screened, metal debris are enabled to be completely separated from the positive pole powder, and the method is combined with an advanced modification technology. The technological process is basically a dry recycling process, thereby avoiding the problems such as secondary pollution caused by acid-alkali leaching and extraction recycling in the traditional wet metallurgy recycling process. The recycled and repaired regenerated cathode material can be directly applied to the production of lithium batteries.

Description

technical field [0001] The invention relates to a method for recovering positive electrodes of lithium batteries, in particular to a method and system for recovering positive electrodes from waste lithium batteries and regenerating them, and belongs to the technical field of lithium battery recovery. Background technique [0002] Lithium and lithium compounds are important energy materials, widely used in energy storage power supply and national defense construction. Lithium-ion batteries have the characteristics of high energy density, high voltage platform, small self-discharge, and no memory effect. They have developed into the main energy source of 3C electronic products, accounting for more than 80% of the consumer electronics market. Benefiting from the high growth of the new energy vehicle industry, domestic power battery shipments were 39.2GWh in 2017, and it is expected that the CAGR will remain above 30% in the next three years. The effective life of the battery o...

AI Technical Summary

Problems solved by technology

For example, in the process technology of alkali dissolution-acid leaching-extraction of nickel, cobalt and manganese, although the extraction efficiency of the solvent extraction method is high and the product purity is high, the organic solvent is more or less dissolved and volatile and pollutes the environment, causing secondary Pollution, and the cost of the extraction method is relatively high, and there are limitations in industrial production

Another example is that due to the similar potential of nickel and cobalt, nickel and cobalt will be deposited synchronously in the electrodeposition technology to form a cobalt-nickel alloy, which will affect the subsequent purification and restrict the expanded application.

Other methods such as ion exchange method, sulfide bacteria leaching, etc. have successfully recovered valuable metal elements, but these methods have certain limitations, such as ion exchange method is more complicated to operate, the steps are more cumbersome, and it is only suitable for the separation and purification of a small amount of ions ; Factors such as the cultivation of sulfur bacteria leaching technology bacteria, harsh conditions of use, and difficulty in industrialization have restricted the application and promotion of the technology

Moreover, the existing waste battery recycling process is basically to precipitate or extract nickel, cobalt and manganese, and then purify the lithium-containing solution, which consumes a lot of acid and alkali and has a lengthy process. The product is the primary raw material for the synthesis of positive electrode materials.

Furthermore, the positive electrode powder recovered by traditional dry method contains a little metal impurities or the original material structure is destroyed during the recovery process. The recovered powder cannot be directly reused or the stability and consistency of the material after simple modification Poor performance restricts recycling

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