Hydrodynamic separation and wet stripping process for waste lithium ion battery broken materials

Abstract

The invention discloses a hydrodynamic separation and wet stripping process for waste lithium ion battery broken materials. The process comprises the following steps of firstly, carrying out crushing and electrolyte low-temperature volatilization or organic matter pyrolysis pretreatment on a waste battery, carrying out hydrodynamic separating on the treated crushed materials to separate out shells, then carrying out one-stage or multi-stage soaking on a sample by using a nucleophilic reagent, due to the fact that the nucleophilic reagent can chemically react with PVDF or aluminum and copper, some reagents can dissolve the PVDF or the aluminum and the copper, therefore, completely stripping and separating leached pole powder from the copper, the aluminum and the like, and improving the recovery rate and grade of the pole powder. According to the process, hydrodynamic force is adopted for efficient and clean pre-sorting of substances such as diaphragms, pole pieces and the shells, the separation effect is greatly improved compared with the prior art, and meanwhile the risks of dust raising, powder explosion and aluminum explosion of traditional wind power winnowing are avoided. The pole powder of the waste lithium ion battery is stripped by adopting a nucleophilic reagent leaching method, the pole powder falling effect is obvious, and the pole powder recovery rate and grade are high.

Description

technical field [0001] The invention belongs to the field of recovery and utilization of secondary resources, and in particular relates to a hydrodynamic sorting and wet stripping process of crushed materials of waste lithium-ion batteries. Background technique [0002] Since its commercialization, power lithium batteries have been widely used in electric vehicles, mobile devices, communication base stations, aerospace and other fields due to their advantages such as high energy density, light weight, good cycle performance, high specific capacity, and no memory effect. At present, lithium-ion batteries are in a stage of rapid development. Taking my country as an example, the total installed capacity of lithium-ion batteries in China in 2017 was 36.91 billion watt-hours, an increase of 21% over 2016. Among them, the total installed capacity of ternary batteries was 16.56 billion watt-hours, accounting for 44.87% of the total installed capacity. The total installed capacity o...

AI Technical Summary

Problems solved by technology

The use of alkaline solution in this invention to treat waste batteries is difficult to implement in industrial production. First, the appropriate concentration of the alkaline solution needs to be controlled, otherwise the alkaline solution will react with metal aluminum, resulting in a reduction in the obtained metal aluminum and even a large amount of hydrogen. bad for production

Chinese invention CN102676827 discloses a technology for recovering nickel and cobalt from waste lithium-ion batteries. The shedding method used is to add N-picoline / N, N-dimethylamide to PVDF in waste batteries. Dissolving to remove the pole powder, but the removal of this method needs to be removed at high temperature to have a good removal effect. With the progress of the battery coating process, the coating and compaction of the positive electrode material is getting higher and higher. Some batteries The powder cannot even be leached out by this type of solution

Chinese invention CN106450542 discloses a technology that uses a broken method to separate lithium manganate pole powder from the current collector. Since the bonding between the positive electrode active material and the aluminum foil depends on the chemical adhesion between PVDF and the aluminum foil, the physical It is difficult to completely separate the broken parts. Even if they can be separated, a large amount of metal will enter the powder, which will bring a lot of difficulties to the subsequent removal of impurities.

Chinese invention CN107293817 discloses a method of pyrolysis, crushing and screening of waste lithium-ion batteries to remove extreme powder, but this method is due to the fact that PVDF may not be completely pyrolyzed during the pyrolysis process, and the other is the pyrolysis process. The electrode powder may be solidified on the metal copper and aluminum, so it is difficult to remove the electrode powder if only the method of crushing and sieving is used.

Chinese invention CN107464963 discloses a pole piece soaked in an organic solvent (such as styrene, tetrachlorethylene) to make the pole powder fall off from the pole piece. These organic reagents all use the principle of similar compatibility to dissolve the organic binder PVDF so that the The electrode powder falls off from the electrode sheet, but this type of method is greatly affected by the battery coating process, and the battery dissolution effect obtained by different coating processes is different, and the dissolution process of organic solvents dissolving PVDF is slow, so the shedding efficiency of this method is relatively low. Low, it is difficult to remove the electrode powder on all used batteries

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