A method for recovering graphite from scrapped lithium-ion batteries

Abstract

The invention relates to a method for recovering graphite from scrapped lithium-ion batteries, which comprises the following steps: after alkali leaching and acid leaching, the waste materials of lithium-ion full batteries after mechanical crushing are obtained to obtain a graphite crude product and a graphite product containing Co, Fe, Ni , the filtrate of Mn metal; the coarse graphite product is sieved to remove the large particle Cu produced in the mechanical crushing of the waste lithium-ion battery, the residual diaphragm after winnowing and the large particle Al that has not been separated and reacted to obtain the first purified graphite Carry out secondary acid leaching treatment to the graphite purified for the first time to remove small particles of Fe and Cu metal impurities therein; stir and wash the reaction product to neutrality, and dry by suction filtration to obtain secondary purified graphite, wherein the acidic filtrate after suction filtration It can be reused in Step 3; the obtained secondary purified graphite is heat-treated in an air atmosphere to remove the conductive agent and binder therein to obtain graphite with higher final purity. The invention has simple process, low cost and energy consumption, and the recovered graphite has excellent stability.

Description

technical field [0001] The invention relates to lithium ion battery recovery technology, in particular to a method for recovering graphite from scrap lithium ion batteries. Background technique [0002] In recent years, lithium-ion batteries used in electric vehicles, energy storage devices, and mobile electronic devices have been increasing year by year. However, these lithium-ion batteries that have been put into the market in large quantities will inevitably face performance degradation and disposal problems after the battery life ends after 3-5 years of use. It is predicted that by 2020, the number of waste lithium-ion batteries in my country will reach 25 billion, a total of 500,000 tons. Scrapped lithium-ion batteries contain a large amount of scarce metals such as nickel, cobalt, manganese, aluminum, copper, etc. These metals also have a cumulative effect and are enriched in the human body through the food chain, causing great harm. In addition, scrapped lithium-ion...

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Problems solved by technology

In addition, most of the current patents are only for the complete negative electrode sheet, and there is less involvement in the scrapped full battery powder containing positive and negative electrodes, separators, and current collectors.

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