Method for recycling negative electrode material of lithium ion battery by wet method

Abstract

The invention discloses a method for recycling a negative electrode material of a lithium ion battery by a wet method. The method comprises the following steps of: dismantling the coiled negative electrode material of the lithium ion battery and spreading into strip carbon-coated copper foils; putting the carbon-coated copper foils obtained by dismantling into a temperature-control washing pool with stirring; pouring tap water into the pool until all the copper foils are immersed; heating to raise water temperature in the pool to 70 DEG C-100 DEG C, and keeping the temperature in the pool between 70 DEG C and 100 DEG C and stirring; stopping stirring after the carbon powder is completely washed off from the copper foils; taking out the copper foil without attached carbon powder after wet-method separation from the washing pool, drying and packaging to finish the recycling of metal copper; transferring a cleaning solution left in the temperature-control washing pool to a sedimentation tank; standing for separation to obtain supernate containing a binder and carbon powder sludge; washing the obtained carbon powder sludge for 3-6 times, and then pumping into a fluidized bed drier for fluidized drying; and recycling the dried carbon powder particles by a dust collector to finish the recycling of the carbon powder.

Description

technical field [0001] The invention relates to the technical field of recovery and reuse, in particular to a wet recovery method for negative electrode materials of lithium ion batteries. Background technique [0002] A lithium-ion battery is a rechargeable battery that primarily relies on the movement of lithium ions between the positive and negative electrodes to function. At present, China's lithium-ion battery output is the world's leading, accounting for about 20%. , The negative electrode material is not less than 6,000 tons; the negative electrode of the lithium-ion battery is composed of about 90% carbon material, 5% acetylene black and 5% organic binder, which are evenly mixed and coated on the copper foil current collector. [0003] Regarding the recycling method of lithium-ion battery negative electrode materials, Chinese patent document CN100440615C (application number 200610154458.8) discloses a recycling method for waste lithium-ion batteries. The recovery me...

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Problems solved by technology

This method treats the positive electrode and negative electrode materials together, so that there are more operating steps; a large amount of organic solvent is used for elution in the separation, which increases the environmental burden on the one hand, and on the other hand has higher requirements on operational safety; although organic solvents can be recycled, but After each use of the organic solvent, the solvent must be purified by distillation, which increases the recovery steps and recovery costs; in addition, the active component graphite in the negative electrode material cannot be recovered if the burning method is selected, although it can be recovered if the sink-float method is selected. Graphite is separated from lithium cobaltate, but the separation method is complicated, and the recovered graphite needs further treatment before it can be recycled

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