WO2008022413A1

WO2008022413A1 - Process for the separation and extraction of used li-ion batteries

Info

Publication number: WO2008022413A1
Application number: PCT/BR2007/000031
Authority: WO
Inventors: Marcelo Bozzo; Maria Do Rosário Fabeni HURTADO; Maria Angela Brotto Baldini Lance
Original assignee: Lg Eletronics De São Paulo Ltda
Priority date: 2006-08-21
Filing date: 2007-02-08
Publication date: 2008-02-28
Also published as: BRPI0605048A

Abstract

Process for the extraction of graffiti and agglutinant in the copper collector to proceed with the separation of negative electrodes, such process comprises the following stages: i) after the extraction of lithium compounds, the negative electrodes are placed in a perforated container, proper to allow the passage of the pulverized material composed of graffiti and agglutinant; such container should be made from plastic, metallic or polymeric material resistant to the acid solution and placed inside a becker, ii) a solution of hydrochloric acid at 2 to 10% is then added to the electrodes for the removal of the graffiti and agglutinant; iii) after ten minutes of mechanical stirring, the graffiti and the agglutinant are released, passing through the holes and the copper remains in the perforated container; iv) such acid solution is filtered, the graffiti and the agglutinant remain in the filter-paper and the acid solution remains in the filtrate; it can be reused in the process for a is few other times; e v) the graffiti and the agglutinant are then dried and weighed and they can be used in the manufacturing of new batteries.

Description

Process for the separation and extraction of used Li-ion batteries "

The present invention refers to a process that allows the separation of negative electrode materials from lithium-ion batteries at the end of their lifespan.

When compared to nickel-cadmium and nickel-metal-hydride, because of the high energy density and the high pressure of lithium, the lithium batteries have been thoroughly investigated and used in cellular phones, as this technology enables the manufacturing of higher capacity and lighter batteries, Consequently, the use of ion-lithium batteries has grown exponentially and, as a result, the disposal increases each year.

In addition to environmental benefits, the lithium-ion batteries reuse assumes great importance, as their components hold a significant economic value, The process comprises the following stages: i) Battery opening; ii) Previous separation of some compounds (metal can, polymeric carcass, metal tapes, etc); iii) The negative electrode is processed, resulting in the separation of the graffiti and the agglutinant in the copper collector, thus obtaining a metallic copper and a mixture of graffiti and agglutinant.

The process to obtain the metallic copper does not comprise the copper dissolution and the precipitation and purification of the compounds obtained. Potential copper contamination of other products obtained during the whole recycling process is also eliminated.

As it is common knowledge among the specialists in the area, the copper is usually used as a conductive material (wires and cables), responsible for 45% of its annual consumption. Other applications are: i) in condenser and piping tubes; ii) in electromagnets; iii) in electric motors; iv) in switches and relays, vacuum tubes and microwave oven magnets; v) as a substitute to aluminum (less conductive) in integrated circuits; vi) in the mint process (copper-nickel alloy), in the manufacturing of sculptures, statues, bells and ornaments (nickel, bronze and silver alloys); and vii) in copper crystal lens for ultra-high-sensitivity medical imaging (radiology).

The growing worldwide demand for high purity metals, the creation of more restrictive environmental regulations, the need to reduce operating costs and achieve economic viability and the gradual reduction of precious metal ores lead the industry to develop increasingly more complex metal purification processes. Reusing metallic copper extracted from lithium batteries through the proposed process is a way of meeting these needs.

The batteries that are not disposed of correctly may result in their compounds being carried away by rivers, rain, wind, and other ways. Copper combined with certain solutions (chloride, acid, etc.) forms copper oxide, which can be leached and carried away. Copper at certain concentrations becomes extremely toxic to animal life, and, depending on the species, it is much more toxic to animals closer to the base of the food chain. Copper toxicity is directly related to the distribution of its individual chemical and physical forms, which, together, contribute to the total concentration. The rate of copper incorporation is high and related to the type of sediment/clay, pH, competitive cations and the presence of iron and manganese oxides.

When the negative electrode is grinded and the copper is dissolved, the traditional chemical precipitation methods are used, which are less selective in some cases.

In most cases, thø extraction of copper from copper oxide is a high energy-consumption process, and therefore can be extremely expensive. Also, there has been an increase in the demand for a process to recover copper from the negative electrode that does not include the grounding and dissolving stages. Another aspect to be considered is that the described process uses only low-cost solvents that are easy to be obtained and handled.

The scientific literature describes a process in which the negative electrode materials are extracted from the collector using ethyl acetate as solvent. The ground material produced during the extraction consists of carbon and agglutinant, which were mechanically removed through grinding, for example.

Based on the aspects related above, *» present invention intends to describe a method to separate the graffiti and the agglutinant from the negative collector and to recover copper in its metallic form.

Another objective is to provide a system to separate the copper from the graffiti and the agglutinant.

The objectives stated previously will be achieved through the process of separating and extracting graffiti and agglutinant from the copper collector, which consists of a method and a system to separate graffiti and agglutinant from the copper collector. After the batteries are opened, the positive and negative electrodes and separators are placed in a water solution in order to liquefy the lithium compounds. When the solubilization process was completed, tile positive electrode material was dissolved in another water solvent in order to obtain aluminum and cobalt compounds and pulverized material containing graffiti and agglutinant. To proceed with the separation of the negative electrodes, they are placed into a container with holes. Such container is placed inside a becker and, next, a hydrochloric acid solution at 5% is added to the electrodes so that both graffiti and agglutinant are removed. After ten minutes of mechanical stirring, the graffiti and the agglutinant are released, passing through the holes. The copper remains in the perforated container. The acid solution is filtered, the graffiti and the agglutinant remain in the filter-paper, and the acid solution remains in the filtrate. It can be reused in the process for a couple of times. The invention is described in details as follows:

Figure 1 shows the flowchart of the whole process. Figure 2 illustrates the design of the system to separate graffiti and agglutinant from the copper collector.

According to the figures, the negative electrodes, after the extraction of the lithium compounds, are placed in a container with holes, proper to allow the passage of the pulverized material composed of graffiti and agglutinant (PVDF, PAN, PMMA on the negative electrodes). It is recommended to use a plastic, metallic or polymeric container resistant to the acid solution. The perforated container is placed inside another container and then a hydrochloric acid solution at 2 to 10% is added to the electrodes. The hydrochloric acid solution must be stirred mechanically or through another method that allows the graffiti and the agglutinant to expand and then to release from the copper cutting device. After ten minutes of mechanical stirring, the graffiti and the agglutinant are released, passing through the holes. The copper remains in the perforated container. The acid solution is filtered, the graffiti and the agglutinant remain in the filter-paper, and the acid solution remains in the filtrate. It can be reused in the process for at least four times. The graffiti and the agglutinant are dried and can be used in the manufacturing of new batteries. They are weighed, generating a mass of 12g/10 batteries (copper) and 31g/10 batteries (graffiti). Besides the economical aspects regarding the recovery and reuse of materials described previously, this invention also contributes to the conservation and preservation of the environment. Although a preferable solution has been described and illustrated, it is important to stress that other solutions can be performed within the same scope.

Claims

1- "PROCESS FOR THE EXTRACTION OF GRAFFITI AND AGGLUTINANT IN THE COPPER COLLECTOR", characterized by the fact that, to proceed with the separation of negative electrodes, such process comprises the foffowing stages: i) after the extraction of lithium compounds, the negative electrodes are placed in a perforated container, proper to allow the passage of the pulverized material composed of graffiti and aggfutinant; such container should be made of plastic, metallic or polymeric material resistant to the acid solution and placed inside a becker; H) a solution of hydrochfσric acid at 2 to 10% is then added to the electrodes for the removal of the graffiti and aggfutinant; iiϊ) after ten minutes of mechanical stirring, the graffiti and the agglutinant are released, passing through the holes and the copper remains in the perforated container; iv) such acid solution is filtered, the graffiti and the agglutinant remain in the filter-paper and the acid solution remains in the filtrate; it can be reused in the process for a few other times; and v) the graffiti and the agglutinant are then dried and weighed and they can be used in the manufacturing of new batteries.