JP3452769B2 - Battery treatment method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery pack of a primary battery and a secondary battery such as a lithium ion battery, a nickel cadmium battery and a nickel hydride battery used as a power source for various electronic devices such as VTRs and communication devices. The present invention relates to a battery treatment method for safely and efficiently recovering and reusing various metals from wastes.

[0002]

2. Description of the Related Art In recent years, as batteries have become higher in capacity, lighter in weight and longer in life, communication devices such as personal computers and mobile phones, electric devices such as portable video cameras,
Batteries are widely used in electronic devices and the like.
Except for some mobile phones, these batteries are commercially available and used in the form of battery packs from the viewpoint of safety and ease of use. In general, a secondary battery is discharged after being charged and discharged several hundreds of times, and the voltage at the time of charging is lowered due to deterioration of the electrodes and the electrolytic solution.

Since such battery packs contain components such as cadmium and lead that should be taken into consideration for environmental problems, the industry association voluntarily considers nickel-cadmium batteries and lead-acid batteries among the current battery packs. It is collected as an industrial raw material and is then recycled as an industrial raw material by requesting a non-ferrous smelter to extract it as cadmium oxide and lead.
Lithium-ion secondary batteries, nickel-hydrogen batteries, etc.
It is incinerated and then landfilled because it is an environmentally friendly battery that does not contain harmful substances.

However, unlike conventional secondary batteries, lithium-ion secondary batteries do not contain metals such as mercury, cadmium, and lead, and have good cycle life in terms of characteristics. It is increasing year by year. For this lithium-ion secondary battery, noble metals designated as national stockpiling materials are used in both the materials currently in the mainstream and the materials listed as candidates for the next generation. Recycling from used lithium-ion secondary batteries is drawing attention. For this reason, currently
From the viewpoint of resource conservation, development of recycling technology for the secondary battery has been active. For example, a technology for roasting a lithium secondary battery and recovering cobalt chloride was developed jointly by Sony Corporation and Sumitomo Metal Mining Company, and was released in 1996.

When the roasting method is suddenly roasted by the above-mentioned roasting method, lead scatters because the substrate is contained in the battery pack, and the PC / ASA casing is decomposed to discharge nitrogen oxides. And exhaust gas treatment equipment is required.
There are many points that need to be dealt with due to environmental issues. In order to deal with these problems, it is necessary to mechanically disassemble the battery pack as much as possible, and to perform heat treatment, wet treatment, etc. only on the portion that needs the culture treatment.

When disassembling the battery pack, some of the waste batteries may include undischarged batteries. If the battery pack is disassembled while the potential is maintained, the circuit is short-circuited by the tool used for disassembly. There is a possibility. A battery pack including a lithium-ion secondary battery may cause an explosion or the like, which is extremely dangerous.

As a method for discharging a waste battery, Japanese Patent Application Laid-Open No. 08-306394 proposes a method of immersing a lithium battery in an ionic conductive liquid for discharging. This proposal discloses that lithium batteries having various shapes are immersed in a saline solution or liquid paraffin in which iron powder is dispersed or mercury to discharge.

Further, regarding the separation and recovery of valuable metals from the lithium ion secondary battery, there is a method of separating and recovering iron, copper, cobalt and the like by using magnetic sorting after roasting and crushing the battery. . The residue obtained by removing iron using magnetic separation after roasting the battery can be separated by sieving to dissolve the acid that has passed through the sieve, and the solvent extraction method to separate and recover cobalt.

[0009]

When a battery or battery pack is discharged using saline according to the above-described discharging method, a large amount of precipitates are generated and the inside cannot be visually inspected, and the conductivity of the battery or battery pack is also reduced. The discharge may be incomplete due to partial erosion of the conductive part, or it may be difficult to measure the residual voltage due to a change in shape and it may be difficult to confirm whether the discharge is completed. What is necessary when discharging the battery or battery pack is that the discharge is performed reliably.If the discharge is incomplete or it is not possible to confirm the completion of the discharge, it is safe to collect the battery or battery pack. I can't do it.

As described above, in order to avoid the danger in the waste battery recovery process, it is necessary to perform the discharge process safely and surely before disassembling the waste battery.

Further, when magnetic separation is used when separating and recovering each metal from the metal mixture after roasting and crushing the battery,
For iron, copper, cobalt, etc. that are sorted and collected by magnetic force, the other components adhering to the collected products are mixed without being separated, so the purity of the collected products is not very good, and the usefulness of the collected products is low. Low.

With respect to the residue after the magnetic separation, relatively high-purity cobalt can be recovered by separating and recovering cobalt through sieving, dissolution with acid, and solvent extraction. The points are insufficient.
Moreover, since the residue on the sieve is a mixture of copper and aluminum, its utility value is low.

An eddy current is generally used for the selection of copper and aluminum, but it cannot be applied to the selection of foil-shaped copper and aluminum such as a battery. Not established.

[0014]

As a result of intensive studies to solve the above problems, the present inventors have developed a discharge method using a liquid with good efficiency and workability.

The inventors of the present invention have also separated the active material by wet or dry method in the electrode taken out from the battery case,
It has been found that the object of the present invention can be achieved by using, for example, selection of a current collector of an electrode with a heavy liquid.

The method of treating a battery according to the present invention is a method of treating a battery having an electrode in which an active material is laminated using a binder as a current collector, the method comprising immersing the battery in an aqueous sulfuric acid solution.
A discharging step for discharging the battery further, and disassembling the battery
Dismantling process and sorting process to select electrodes from disassembled batteries
And an active material that separates the electrode into the current collector and the active material.
Quality separation step and metal step for recovering metal components from the active material
In the active material separation step, the current collector and the active material are separated by immersing the electrode in an acid solution to erode the binder.

Further, the battery treating method of the present invention uses a current collector.
A method of treating a battery, comprising an electrode in which an active material is laminated using a binder made of a resin containing halogen , wherein the electrode is 300 to 400 in a hydrogen / argon mixed gas atmosphere.
The current collector and the active material are separated by heating to ° C to decompose the binder.

Furthermore, the method for treating a battery of the present invention is a method for treating a battery having a copper current collector and an aluminum current collector, wherein the copper current collector and the aluminum current collector have a specific gravity of 1 Separation is carried out by specific gravity selection using a heavy liquid of 9 to 2.9 g / ml.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION A battery or a battery pack has positive and negative electrodes, an electrolytic solution, and a casing that covers these, and the electrodes are a current collector that constitutes the main body of the electrode and a surface of the current collector. It is composed of a layer of an active material which is formed into a film and exchanges electrons and ions to protect the surface of the current collector. The current collector is made of aluminum for the positive electrode and copper for the negative electrode, and the positive electrode is LiC for the active material.
In general, carbon or the like is used for oO ₂ and the negative electrode.
The active material is deposited and laminated on the surface of the current collector using PVdF or the like as a binder. In order to safely recycle metals such as lithium, cobalt, copper, and aluminum from such batteries and battery packs, disassembling work is performed to separate the electrodes from the housing and the electrolyte, and the electrodes are made into an active material and a current collector. It is necessary to separate each metal and recover each metal. Further, in order to safely perform the disassembly work, it is necessary to discharge the battery and the battery pack.

In consideration of the above, in the present invention, as shown in FIG. 1, the battery and the battery pack are disassembled (step 2) through a discharge treatment (step 1 in the figure), and the disassembled article is washed (step 3). ) Collects the electrolyte in the battery and removes the iron-based components that make up the casing by magnetic force selection (not shown).
After that, each metal component constituting the current collector of the electrode and the active material is recovered. Two methods, wet processing and dry processing, have been proposed for the treatment of this electrode.
Aluminum, cobalt, lithium, etc. are recovered. The electrode can be separated into a positive electrode and a negative electrode by performing a specific gravity selection (step 4) before performing a wet or dry process, which contributes to improvement of recycling efficiency. Copper of the current collector can be recovered by heating the negative electrode to remove carbon as the active material.

The wet treatment is a treatment method in which the current collector and the active material layer are separated by impregnating with sulfuric acid or nitric acid (step 5), and the positive electrode active material is dissolved in acid (step 6) to adjust the pH. By adjusting (step 7), cobalt and lithium are separated and recovered, and together with the sulfuric acid used in step 5, pH adjustment (step 8), electrolysis (step 9), pH adjustment (step 10), and aluminum. , Copper, cobalt, and lithium can also be recovered. The dry treatment is performed by heating (step 11) to remove the binder by separating the current collector and the active material layer, dissolving the active material in an acid (step 12), and performing electrodialysis (step 13). Cobalt and lithium are recovered.

First, in the present invention, the discharging process (process 1) of a waste battery and a waste battery pack is performed using a conductive liquid. Generally, a battery pack usually has a plurality of positive and negative terminals. In order to discharge from such a plurality of terminals, the positive electrode and the negative electrode must be connected to each other, and the work is very complicated and structurally impossible if an ordinary connecting means such as a connecting plug is used. In some cases, it is not universal. However, as long as it is a conductive liquid, it can enter any gap of any shape, so by immersing the terminals in such a liquid, multiple terminals can be connected and discharge between the positive and negative electrodes is easy. To be done. Therefore, the problem associated with such a structure is solved, and the discharge can be performed regardless of whether it is a single cell or a battery pack.

In general, in a 3.6V lithium-ion secondary battery, when discharging through an oxide resistance of about 10Ω, one lithium-ion secondary battery is completely discharged within half a day without causing troubles due to heat generation. be able to. Therefore, it is preferable to use a liquid that enables such a discharge as the electrode connecting liquid for discharge (hereinafter, referred to as a discharge liquid).

The requirements for such a discharge liquid include (1) one that does not cause corrosion and erosion due to electrolysis during discharge, and (2) one that can suppress the temperature change due to discharge to about 1 K / hour. Especially regarding (2), if the temperature of the discharge liquid is likely to change, problems such as vaporization due to overheating of the liquid may occur, so caution is required. However, this does not mean that the heating of the discharge liquid is denied, but means that the temperature control of the discharge liquid is easy.

The condition of the temperature change of (2) is the minimum interelectrode distance L [m], the maximum pack voltage V [V], the electric conductivity κ [S / m] of the liquid, and the specific gravity ρ [kg / m of the liquid. ³ ] and the specific heat of the liquid C [J / K · kg], it can be expressed by the following calculation formula.

ΔT [K / hour] = (3600 κV ² ) / (ρL ² C) ≦ 1 As a liquid satisfying the condition (2), for example, pure water or city water,
There are isobutyl alcohol and the like, which also satisfy the condition (1).

Generally, the distance between the electrodes is about several millimeters, and the electrode terminals are at most about 0.2 to ¹ cm ² , but city water or the like has a conductivity of about 10 ^-8 S / cm and a resistance value of 10 as well.
It is about MΩ, and a generally used battery pack of about several to ten and several volts can be discharged without problems. In the case of pure water, the resistance is large and it takes a long time to discharge, but an appropriate discharge liquid can be prepared by adding an electrolyte and increasing the conductivity within the conditions that satisfy the above equation.

As the electrolyte, there are various acids and bases such as mineral acids, organic acids, metal hydroxides, ammonia, amino and imino compounds, and salts thereof, but halogen ions are used as the discharge liquid for batteries and battery packs. A non-producing electrolyte is suitable. If an aqueous solution of an electrolyte that produces halogen ions, such as hydrochloric acid or salt, is used as the discharge liquid, a large amount of precipitates will be generated and the discharge liquid will be suspended, and the positive electrode terminal will be eroded, resulting in unstable discharge. Frequently, it becomes difficult to measure the residual voltage. Also, the discharge liquid may penetrate into the battery pack. It is considered that this is caused by elution of copper used in batteries and battery packs and the elution of copper as copper halide. A circuit board may be installed near the terminals of a battery pack of a portable video camera, and when a battery pack having a circuit board is immersed in a discharge solution containing halogen ions, the copper of the circuit board elutes. The circuit may be opened and the discharge may stop.

Therefore, it is important to use a discharge liquid containing no halogen ions in order to perform discharge processing without separating various kinds of waste batteries and waste battery packs. For example, sulfuric acid, nitric acid, carbonic acid, acetic acid, organic acids, salts of these acids, and metal hydroxides can be used.
Among these electrolytes that do not generate halogen ions, sulfuric acid has particularly good discharge performance and produces few precipitates.

FIG. 2 shows changes with time in the residual voltage when the battery is discharged using an aqueous solution in which an electrolyte is dissolved as a discharge liquid. The symbols in the figure respectively use the following aqueous electrolyte solutions. It shows the case of measurement.

A, B, C: Water D, E: 1M sodium chloride aqueous solution F: 1M sodium hydroxide aqueous solution G: 1M calcium carbonate aqueous solution H: 1M magnesium oxide aqueous solution I: 1M calcium oxide aqueous solution J: 1M sulfuric acid aqueous solution K: 0.5M sulfuric acid aqueous solution L: 0.5M sodium sulfate aqueous solution M: 0.001M sodium sulfate aqueous solution N: 1M hydrochloric acid aqueous solution O: 1M nitric acid aqueous solution Although the discharge characteristics of the battery are different depending on the individual difference, from FIG. It is understood that the higher the concentration of, the better the dischargeability, and a similar tendency is seen in the dischargeability of the electrolytes other than the sulfuric acid aqueous solution. In addition, the dischargeability of the sulfuric acid aqueous solution is particularly good. During the discharge treatment, when the sodium chloride aqueous solutions of D and E were used, a large amount of precipitate was generated, the positive electrode terminal was eluted, and the inflow of the sodium chloride aqueous solution was observed inside the battery. In the N hydrochloric acid aqueous solution and the O nitric acid aqueous solution, the elution of the positive electrode terminal was severe, and the voltage could not be measured after the discharge time of 4 hours.

When an aqueous solution of sulfuric acid is used as the discharge liquid, stable discharge is performed. However, if an excessively high concentration sulfuric acid aqueous solution is used, there is a risk that it will react with components (organic resins, etc.) other than the metals that make up the battery package. preferable.

When discharging, gas is generated from the positive electrode terminal and the negative electrode terminal by the electrolysis reaction. Since the discharge is promoted by removing them, the discharge time can be shortened by additionally using the stirring operation of the discharge liquid. Hydrogen generated from the negative electrode may be separately collected and used as a hydrogen resource.

It is also possible to raise the pH of water by raising the temperature of the discharge liquid and shorten the discharge time by increasing the electric medium. Such physical factors can be appropriately selected depending on the situation.

Since it is sufficient for the discharge process to form a circuit with a liquid, for example, as shown in FIG. 3, only the electrodes E1, E2 and E3 of the battery packs B and B ′ are immersed in the discharge liquid 21 in the discharge tank 20. You may In FIG. 3, reference numeral 22 is a partition plate. Further, the circuit may be formed not only by the immersion method but also by the injection method, or may be formed by using a sponge impregnated with a liquid.

As described above, the battery and battery pack that have been subjected to the discharge treatment are disassembled (step 2 in FIG. 1) and then washed (step 3) to remove the electrolytic solution, and the casing or the like is removed by magnetic force selection or the like. After removing the iron-based constituents, the positive electrode and the negative electrode are separated by specific gravity selection (step 4). This specific gravity selection is performed using a heavy liquid whose specific gravity is adjusted to 1.9 to 2.9, and the positive electrode in which the current collector that is the main body of the electrode is made of aluminum and the negative electrode in which the current collector is copper are Utilizing the difference in specific gravity of. Such a heavy liquid can be prepared using a magnetic fluid such as farosilicon or ferricolloid. When an electrode used in a battery or a battery pack is put into such a heavy liquid and gently stirred for several minutes, the positive electrode sinks and the negative electrode floats. Therefore, the copper used as the current collector can be recovered from the separated negative electrode.

The selected electrodes are separated into a current collector and an active material. This separation can be performed according to a wet process or a dry process.

The wet treatment is a method in which the electrode current collector and the active material are separated by immersing the electrode in an acid. An acid enters between the current collector and the active material, and the current collector is dissolved in a slight amount, whereby the active material is peeled off. The acid used is preferably sulfuric acid, and the concentration of the solution must be 12 N or less. If you use a concentration higher than 12
A large amount of the aluminum current collector is dissolved, and the aluminum recovery rate is reduced. However, if the concentration of sulfuric acid is too light,
It takes a long time to separate the current collector and the active material, which is not preferable. Therefore, the concentration is 0.5 to 10 N, especially 1 to 3
The prescribed one is desirable.

By the above operation, the positive electrode active material is separated from the aluminum current collector at the positive electrode, and the carbon powder as the negative electrode active material on the copper current collector is separated at the negative electrode. First, the positive electrode active material LiCoO 2 is removed from the acid solution by a separation operation such as filtration.
_2. Collect aluminum collector and copper collector. Further, the positive electrode active material is separated into an aluminum current collector and a copper current collector by a separating means such as filtration. The active material is formed in a very thin foil shape, and there is not much difference in size from the current collector, but since it becomes a small piece with a small mechanical force, the active material peeled from the current collector is sieved. It is possible to separate by a mechanical method using. In this case, it is preferable that the size of the electrode to be wet-processed is about 2 cm square. When the crushed size is small, it becomes difficult to separate the current collector from the active material.

The separated positive electrode active material is dissolved in an acid such as a hydrochloric acid solution and then brought into contact with an alkaline solution to cause cobalt hydroxide to break off. Therefore, this should be filtered, washed with water, dried and fired. Can be recovered as cobalt oxide.

Alternatively, after dissolving the positive electrode active material in an acid, the sulfuric acid stripping solution used for separating the current collector and the active material is combined, and aluminum, copper and cobalt contained in a small amount in the sulfuric acid stripping solution are sequentially recovered. May be. Recovery of aluminum is performed by precipitating aluminum from the solution and separating it from the solution. This is possible by bringing the pH of the solution closer to the neutral range and precipitating and separating it as aluminum hydroxide. Particularly, when phosphoric acid or a phosphate is used as a precipitant, the coprecipitation amount of cobalt is small and Can be completely precipitated. The amount of the precipitant used may be equal to or more than the amount of aluminum ions present in the solution, but it is affected by the metals other than aluminum present in the solution and the content thereof, and therefore the solution should be analyzed beforehand. It is desirable to determine the amount used. Copper can be recovered from the liquid from which aluminum has been removed by further electrolytic separation, after which copper is brought into contact with an alkaline solution to form cobalt hydroxide, which is filtered, washed with water, dried,
Cobalt oxide can be recovered by firing.

When the specific gravity separation is not performed before the wet treatment, the aluminum current collector and the copper current collector obtained by the wet treatment may be separated by specific gravity selection using a heavy liquid. In this case, the specific gravity of the heavy liquid is preferably about 1.9 to 2.9, and a methylene iodide / benzene mixed liquid or the like can be used, but it is not limited to this.

When the current collector and the stripped active material are separated from the sulfuric acid stripping solution, the separator and the separator used are charged into an overflow-type stirrer using water without being overflowed and stirred, It is practical to remove the separator floating on the water surface by standing and then to separate and collect the aluminum current collector and the copper current collector by stirring in an overflow state.

The dry treatment of the electrode is performed by heating the separation of the current collector and the active material layer (step 11 in FIG. 1) to remove the binder. The heating is performed in a reducing atmosphere and the temperature is about 300 to 400 ° C. A material containing halogen such as PVdF (polyvinylidene fluoride) is used as the binder of the electrode, and when this is heated to about 300 ° C., it is decomposed and fluorine is desorbed. The desorbed fluorine becomes a corrosion source of the positive electrode current collector (aluminum) and the furnace material. Therefore, heating is performed in a reducing atmosphere to prevent corrosion and deterioration of the current collector and the furnace material. As the reducing atmosphere, for example, hydrogen / argon mixed gas is used. The amount of hydrogen supplied may be equal to or more than the amount of halogen contained in the binder, but in consideration of safety, it is preferably set to 3% or less which is the explosion limit concentration. The current collector and the active material are separated by the thermal decomposition of the binder. The separation of the separated current collector and active material can be performed mechanically using a sieve or the like as described above.

The active material is dissolved in an acid (step 12) and electrodialysis (step 13) is carried out to deposit cobalt and lithium as hydroxides. If this is filtered, washed with water, dried and baked, it is recovered as an oxide. As shown in FIG. 1, in both wet treatment and dry treatment, recovery of cobalt and the like from the active material is carried out after being once dissolved in an acid. Therefore, in any case, electrodialysis is performed even after pH adjustment (step 7). (Step 13) may be performed.

A nickel battery can be treated in the same manner, and is recovered as a hydroxide or an oxide through the same process as cobalt and lithium.

[0047]

The present invention will be described in more detail below with reference to examples.

(Example 1) When the voltage of the battery pack for the IBM personal computer ThinkPad 560 was measured, a voltage between terminals of 6.4V was shown.

City water of 25 ° C. was placed in a transparent acrylic discharge container, and the battery pack was fixed by positioning so that only the electrodes of the battery pack described above were immersed in the city water and discharged. When the residual voltage was measured at any time, discharge was performed according to the curve approximated by the following formula, and the final residual voltage dropped to 0.18V.

V = 6.41 exp (-0.90 t) (V: residual voltage [V], t: time [hour]) At that time, hydrogen was generated from the negative electrode, and copper was broken out near the positive electrode. , No other chemical reaction occurred inside the container. The temperature change was within the measurement error range.

After discharging, the battery pack was disassembled using a general cutting tool. During work, lithium ion 2
Although a part of the protective cover of the secondary battery was broken and the positive electrode and the negative electrode were short-circuited, there was no ignition, smoke, or explosion, and the disassembly work could be completed safely.

Example 2 When the voltage of Tokyo Digital Phone DP-172 battery pack TS-B5-02 with a new vibrator was measured, a terminal voltage of 1.79 V was shown.

A transparent acrylic discharge vessel was charged with 0.1 at 18 ° C.
An M NaOH aqueous solution was added, the battery pack was fixed by positioning so that only the electrode of the battery pack was immersed in the NaOH aqueous solution, and the battery was discharged. When the residual voltage was measured at any time, discharge was performed according to the curve approximated by the formula below, and the final residual voltage dropped to 0.41V.

V = 1.79exp [-0.33t] (V: residual voltage [V], t: time [hour]) At that time, hydrogen was generated from the negative electrode and oxygen was generated from the positive electrode. A black film was found on the surface of the positive electrode. No particular breakouts were found in the vicinity. No other chemical reaction occurred inside the container. The temperature change was within the measurement error range.

After discharging, the battery pack was disassembled using a general cutting tool. During the work, I broke a part of the protective cover of the lithium-ion secondary battery and short-circuited the positive electrode and the negative electrode.
There was no ignition, smoke, or explosion, and the dismantling work could be completed safely.

Comparative Example 1 A battery pack of the same type as that treated in Example 1 was carefully disassembled before the discharge treatment. When the outermost battery film was broken with a cutting tool, some short circuits occurred and smoke was generated. After dismantling the pack,
Each battery was divided and immersed in city water under the same conditions as in Example 1. When the residual voltage was measured at any time, discharge was performed according to the curve approximated by the following formula, and the final residual voltage dropped to 1.03V.

V = 2.55exp [-0.10t] (V: residual voltage [V], t: time [hour]) (Example 3) The electrode collected from the lithium-ion secondary battery was 5 mm square. Cut into.

A heavy liquid having a specific gravity of 2.0 was prepared using farosilicon, charged into a tank having a drain at the bottom, and a chopped electrode was added thereto and stirred. It was separated into a floating electrode and an electrode that settled under the heavy liquid. When the stirring was stopped and the electrode that settled from the drain to the bottom of the heavy liquid was discharged together with the heavy liquid and separated from the heavy liquid by a 1 mm mesh net, a positive electrode using aluminum as a current collector was selectively obtained.

(Example 4) Five electrodes collected from a waste battery were used.
It was cut to a size of mm square.

Magnetic fluid (ferri colloid) has a specific gravity of 2.5
Prepare the heavy liquid of and put it in a tank with a drain at the bottom,
The cut electrode was added to this, and the strength of the magnetic field was made strong by an electromagnet to stir the heavy liquid. After about 5 minutes, the electrode floated on the liquid surface due to buoyancy and separated into the electrode settling at the bottom of the heavy liquid. When the stirring was stopped and the electrode settling from the drain to the lower part of the heavy liquid was discharged together with the heavy liquid and separated from the heavy liquid with a 1 mm mesh net, a positive electrode using aluminum as a current collector was selectively obtained.

Example 5 An electrode taken out from a used lithium ion secondary battery using lithium cobalt oxide (LiCoO 2) as a positive electrode active material was cut into 5 cm squares, and 1 kg of the cut electrode was placed in a polypropylene container. 0.8
When 2 liters of a normal sulfuric acid aqueous solution was added and the container was rotated for 1 hour, lithium cobalt oxide of the positive electrode was peeled from the aluminum current collector, and carbon powder of the negative electrode active material was also peeled from the copper current collector. The aqueous solution of sulfuric acid was filtered with a paper filter to separate the solution from the solid. Next, the solid matter was put into a polypropylene 10 mm × 10 mm sieve, sprayed with water, and lithium cobalt oxide was passed through the sieve together with water and collected in a beaker. The separator, the aluminum current collector, and the copper current collector were collected on the sieve.

After water was removed from the lithium cobalt oxide in the beaker by decantation, hydrochloric acid was added and dissolved by heating to obtain a solution of cobalt complex ions. After cooling this to room temperature, a sodium hydroxide solution was added until it reached pH 10, cobalt hydroxide was precipitated, and this was filtered, washed, dried and calcined to recover as cobalt oxide.

On the other hand, the separator, the aluminum current collector and the copper current collector on the sieve were put into 2 liters of a heavy liquid having a specific gravity of 3.3 prepared by diluting methylene iodide with benzene and stirred for 10 minutes. After standing still, the separator on the liquid surface was first removed, then the aluminum foil was taken out, and finally the copper foil was taken out.

Amount of electrode treated and amount and ratio of cobalt, aluminum, copper recovered in the above method,
Table 1 shows the amount and composition ratio of the electrode per untreated battery as known data. In addition, the recovery rate calculated from the results of Table 1 is shown in Table 2, and the amount of impurities in the recovered material in this method is shown in Table 3.

[0065]

[Table 1] −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−               Processing amount Recovery amount (g) Ratio (%)               (G) Co Al Cu Cu Co Al Cu −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Example 5 1000 250 73 190 25.0 7.30 19.0           ----------------- (23.1 6.24 1.84 4.48 27.0 7.97 19.4 per battery) −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

[Table 2]

[Table 3] −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−                                   Impurities (%) in recovered materials                           Fe Co Al Cu Cu Ni Li −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Cobalt (cobalt oxide) 0.010 − 0.015 0.020 0.020 0.005 Aluminum 0.005 0.006 − 0.017 0.005 <0.004 Copper 0.005 0.005 0.0020 − 0.024 <0.005 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

When sulfuric acid concentrations of 3N, 4N and 5N were used in the stripping step, the cobalt recovery rates were 91.4%, 88.8% and 8%, respectively.
6.9%, copper is 95.4%, 93.5%, 9
It was 1.2%. Aluminum is 64.3 each
%, 56.2% and 35.5%. This result shows that the recovery rate decreases as the sulfuric acid concentration increases, and it was particularly remarkable in the case of aluminum.

Comparative Example 2 The electrode was treated in the same manner as in Example 5 except that 1N hydrochloric acid, 6N hydrochloric acid and 12N hydrochloric acid were used as the stripping solution instead of sulfuric acid. Also, the aluminum current collector was completely dissolved. Therefore, it was difficult to recover aluminum.

Comparative Example 3 The electrode was treated in the same manner as in Example 5 except that 1N nitric acid, 6N nitric acid and 12N nitric acid were used as the stripping solution instead of sulfuric acid. The current collector was almost completely dissolved. Therefore, it was difficult to recover copper.

(Example 6) In the same manner as in Example 5, lithium cobalt oxide, aluminum and copper were separated as solids. In the step of recovering lithium cobalt oxide as cobalt oxide, the cobalt complex ion obtained by decomposing lithium cobalt oxide with hydrochloric acid was mixed with the sulfuric acid stripping solution filtered after the sulfuric acid stripping. Sodium hydroxide solution was added to this mixed solution to adjust the pH to 4.

Next, 100 parts of sodium hydrogen phosphate powder is added.
g was added and mixed, and aluminum complex ions contained in the sulfuric acid stripping solution were precipitated as aluminum phosphate. After removing this precipitate using a filter paper, sulfuric acid was added to the filter liquid. The solution was electrolyzed for 2 hours by passing a current of 0.5 A using a platinum electrode to remove copper contained in the filtrate. Cobalt oxide was recovered from the copper-free solution according to the method used in Example 5.

Table 4 shows the recovery amounts and ratios of cobalt, aluminum and copper in the above method, the recovery rate is shown in Table 5, and the impurities in the recovered products are shown in Table 6.

[0072]

[Table 4] −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−               Processing amount Recovery amount (g) Ratio (%)               (G) Co Al Cu Cu Co Al Cu −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Example 6 1000 265 74 191 26.5 7.40 19.1 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

[Table 5]

[Table 6] −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−                                 Impurities (%) in recovered materials                           Fe Co Al Cu Cu Ni Li −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Cobalt (cobalt oxide) 0.004 − 0.015 0.020 0.020 0.005 Aluminum 0.005 0.006 − 0.017 0.005 <0.004 Copper 0.005 0.005 0.002-0.024 <0.005 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

Example 7 Lithium cobalt oxide was separated from the aluminum current collector and the copper current collector by the method of Example 5 to recover cobalt as cobalt oxide, and then a separator on a sieve, an aluminum current collector and The copper current collector was put into an overflow-type stirring device using water, and stirring was performed for 10 minutes with a metal rod from the upper part of the device without overflowing. After standing for 5 minutes, the separator floating on the water surface was removed. Next, let the aluminum current collector overflow with the water while stirring in the overflow state,
It was collected on a wire mesh provided outside the device. Finally, the apparatus was stopped, the water was drained, and the copper current collector remaining in the apparatus was collected.

Table 7 shows the recovery amounts and ratios of cobalt, aluminum and copper of the above method, and Table 8 shows the recovery rates.

[0075]

[Table 7] −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−               Processing amount Recovery amount (g) Ratio (%)               (G) Co Al Cu Cu Co Al Cu −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Example 7 1000 254 71 190 25.4 7.10 19.0 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

[Table 8]

Example 8 When the voltage of the battery pack for the personal computer ThinkPad 560 manufactured by IBM was measured, the terminal voltage was 6.9V. When the terminals of this battery pack were immersed in a 0.1 M H ₂ SO ₄ aqueous solution and discharged for 6 hours, the voltage between the terminals dropped to 0.5V.

By heating this in an oven at 130 ° C., the polycarbonate resin casing of the battery pack and the alloy fusion part of the acrylonitrile-styrene acrylate resin are peeled off, and the internal circuit board and lithium ion secondary battery (A
& TB LSR17500) and other parts were recovered.

First, a lithium ion secondary battery (cylindrical)
Was divided into two parts in the axial direction, and further, the lower part of the spacer and the part just above the negative electrode terminal surface where only the separator was present were cut. Next, this was immersed in alcohol having a flash point of 40 ° C. or higher to convert the precipitated lithium into alcoholate, and at the same time, the electrolytic solution was washed with alcohol. Furthermore, stirring was performed and the separator was removed by specific gravity selection.

The casing (soft iron) and the like are removed from the remaining casing, positive electrode and negative electrode by magnetic force selection, and the positive electrode, negative electrode and other resins are removed using a specific gravity sorter (Harada Sangyo). Classified. The negative electrode was immersed in water and irradiated with ultrasonic waves of 40 KHz to remove carbon as an active material, remove the copper current collector and evaporate water to recover carbon. This carbon was usable as a reducing agent for iron making. On the other hand,
The copper current collector was dried and then pressed. The purity of this copper is 90wt
% Or more, and could be directly added to the secondary refining process of the copper blast furnace.

The positive electrode was introduced into a calcining furnace and heated to 400 ° C. in a reducing gas atmosphere (hydrogen 1%, argon 99%) to remove the binder (fluorine resin) contained in the positive electrode active material. Removed. After discharging from the furnace, this was introduced into trommel and the positive electrode active material LiCoO ₂ and the positive electrode current collector aluminum foil were separated with a sieve of φ5 mm. Aluminum foil was pressed.

The positive electrode active material was dissolved in a 1 M aqueous hydrochloric acid solution heated to 70 ° C., and carbon, etc., which did not dissolve and floated, was filtered off.

The filtrate was introduced into the electrodialysis chamber shown in FIG. 4 and migrated through a dialysis membrane to move and separate lithium and cobalt ions to the negative electrode side and chlorine ions to the positive electrode side. In FIG. 4, reference numerals 30 and 31 are anion permeable membranes, reference numerals 32 and 33 are cation permeable membranes, and reference numerals 34 and 3 are shown.
Reference numerals 5, 36 and 37 denote bipolar films. In this electrodialysis chamber, hydroxide ions and hydrogen ions generated using a bipolar membrane are introduced into the solution of each electrode, and lithium and cobalt are precipitated as hydroxides from the solution on the negative electrode side. Then, it was dried and recovered as an oxide. Impurities in this oxide were 0.01 wt% or less. On the other hand, the chlorine ions on the positive electrode side were reused as hydrochloric acid to dissolve the positive electrode active material.

Example 9 LiNiO as a positive electrode active material
_The prototype battery coated with ₂ was discharged, decomposed, sorted by specific gravity and calcined by the same operations as in Example 8, and the positive electrode active material was dissolved in hydrochloric acid and introduced into an electrodialysis chamber for electrophoretic separation. It was Hydroxide ions and hydrogen ions generated using a bipolar membrane are introduced into the solution of each electrode of the dialysis chamber to deposit lithium and nickel as hydroxides from the solution on the negative electrode side,
This was dried and collected as an oxide. Impurities in this oxide were 0.01 wt% or less. On the other hand, chloride ions on the negative electrode side were reused as hydrochloric acid for dissolving the positive electrode active material.

(Example 10) The battery pack used in Example 8 and the prototype battery of Example 9 were combined, and discharged, decomposed, sorted by specific gravity, and calcined by the same operation as in Example 8. The positive electrode active material was dissolved in hydrochloric acid and introduced into the electrodialysis chamber shown in FIG. 5 for electrophoretic separation. In the electrodialysis room of FIG. 5, reference numerals 40, 41 and 42 are cation permeable membranes,
The cation permeable membrane 40 is a monovalent ion permeable membrane, and the cation permeable membrane 41 is a divalent ion permeable membrane. Reference numeral 43 is an anion permeable membrane, and reference numerals 44, 45, 46 and 47 are bipolar membranes. Hydroxide ions and hydrogen ions generated using a bipolar membrane are introduced into the solution at each electrode in the dialysis room,
Lithium hydroxide and a mixture of cobalt hydroxide and nickel hydroxide were recovered. The purity of lithium hydroxide is 9
The amount of impurities in the mixture of 9.90 wt% and cobalt hydroxide and nickel hydroxide was 0.01 wt% or less. On the other hand, chloride ions on the negative electrode side were reused as hydrochloric acid for dissolving the positive electrode active material.

(Example 11) The same operation as in Example was repeated to separate ions using the electrodialysis chamber of FIG.
A liquid containing Ni ²⁺ and Co ²⁺ was introduced into the electrolysis tank. The standard end pole potential of Ni ²⁺ was −0.250 V and Co ²⁺ was −0.277 V. Using this, Ni was deposited and recovered. After recovering Ni, cobalt was recovered as hydroxide. The purity of the recovered cobalt hydroxide is 99.9.
It was 8 wt%.

(Embodiment 12) A battery pack for a personal computer GT-R575 081CS manufactured by Toshiba is used with 1M Na ₂
It was immersed in an SO ₄ aqueous solution and sufficiently discharged. Since the battery pack has a switching circuit in addition to the power supply circuit with the outside, discharge by liquid immersion is extremely effective regardless of the shape. Further, the chlorine-based aqueous solution is highly reactive in that chlorine is generated and a large amount of chloride is deposited, but the sulfuric acid-based solution has the merit of facilitating the treatment without such a phenomenon.

The battery pack was placed on a biaxial coarse crusher,
The substrate, the lithium ion secondary battery main body, the pack resin, etc. were exposed from the battery pack, and only the lithium ion secondary battery main body was separated by the magnetic force sorting device. This was put into a medium crusher and crushed to a size of about 5 mm square, and the crushed pieces were washed with 2-propanol to remove the electrolytic solution. At this time, a separator or the like having a smaller specific gravity than 2-propanol was removed. Furthermore, put it on a gravity sorter (made by Harada Sangyo),
The negative electrode, the separator and the like were separated from the positive electrode.

The separated positive electrode was dipped in a 1 M nitric acid aqueous solution and stirred, and the positive electrode active material was peeled off, filtered, and collected.
The mixture was poured into a 1 M hydrochloric acid aqueous solution heated to 0 ° C. and stirred to dissolve it. Insoluble carbon and the like were removed by filtration. The filtrate was electrodialyzed in the same manner as in Example 8 to recover a hydroxide mixture of cobalt and lithium. The amount of impurities in this recovered product was 0.01 wt% or less.

(Example 13) A prototype battery using aluminum as a casing was crushed into small pieces of 5 mm square by a biaxial crusher,
This was washed with n-octanol. The separator and the like that floated on the cleaning liquid were removed and filtered to remove the cleaning liquid. The solid residue was applied to a specific gravity sorter (manufactured by Harada Sangyo) to separate it into an aluminum casing and a positive electrode and a negative electrode. By repeating the same operation as in Example 8 for the positive electrode and the negative electrode, cobalt hydroxide having an impurity amount of 0.01 wt% or less was recovered. The aluminum casing was pressed together with the aluminum foil collected from the positive electrode. This could be used as a raw material for aluminum refining.

Example 14 A card-shaped polymer lithium secondary battery containing PAN, EC and PC as main constituent materials was put on a biaxial shredder having a blade width of 5 mm and cut into a size such that the inside was exposed. The cut product was dipped in a hydrochloric acid solution and irradiated with ultrasonic waves to disperse the electrolytic solution while dissolving and ionizing lithium. Undissolved resins were removed by filtration, and only monovalent lithium was recovered as hydroxide. As a result, the finally obtained lithium hydroxide had a purity of 99.9 wt%.

Example 15 A card-like polymer lithium secondary battery containing PEO, PPO, EC and PC as main constituent materials was treated by repeating the same operation as in Example 14.
As a result, lithium hydroxide having a purity of 99.9 wt% was recovered.

Example 16 A PHS with a built-in lithium ion secondary battery was roughly crushed using a crusher having a blade width of about 2 cm, and a substrate, a liquid crystal panel, a battery and a vibrator were taken out. The secondary battery was recovered from this and the same operation as in Example 13 was carried out to obtain lithium hydroxide having a purity of 99.9 wt%, nickel hydroxide having a purity of 99.9 wt%, and a purity of 99.99 wt%.
Of cobalt was recovered.

On the other hand, the circuit board is heated to 200 ° C. in an oven, and the capacitors, resistors, and
Parts such as IC were removed. Then, it was immersed in a 1.0 M hydrochloric acid aqueous solution heated to 60 ° C. to dissolve and ionize lead and copper.

The undissolved resin portion was filtered and separated, and the filtrate was introduced into an electrodialysis chamber for electrophoretic separation. A liquid on the negative electrode side containing copper ions and lead ions was electrolyzed to recover copper, and then hydrogen sulfide was blown into the solution to recover lead as lead sulfide.
After the treatment, the aqueous solution was introduced into the electrodialysis chamber again, and the concentration operation was repeated to remove it.

Chloride ions on the positive electrode side of the electrodialysis room are
It was reused as an acid together with hydrogen ions generated by the bipolar film.

Comparative Example 4 A battery pack similar to that used in Example 8 was roasted, then crushed, iron contents were removed by a magnetic separator, and then separated into aluminum, copper and powder using a sieve. The powder was dissolved in acid, insoluble material was removed, and then caustic soda was added to recover cobalt hydroxide and nickel hydroxide. The recovery rate of cobalt and nickel was 90.0 wt%.

[0097]

Industrial Applicability The valuable metals such as aluminum, copper and cobalt can be almost completely separated and recovered from used batteries and battery packs very easily, inexpensively and safely, and the recovered products can be highly pure products. . Therefore, the utility value of the recovered material is high, and it greatly contributes to the recycling industry.

[Brief description of drawings]

FIG. 1 is a flowchart showing an embodiment of a method for treating a battery or a battery pack according to the present invention.

FIG. 2 is a graph illustrating discharge efficiency in a method for treating a battery or a battery pack according to the present invention.

FIG. 3 is a schematic perspective view showing an example of a discharge tank for performing a discharge treatment in the method for treating a battery or a battery pack according to the present invention.

FIG. 4 is a schematic configuration diagram showing an example of an electrodialysis chamber for performing electrodialysis in the method for treating a battery or a battery pack according to the present invention.

FIG. 5 is a schematic configuration diagram showing another example of an electrodialysis chamber for performing electrodialysis in the method for treating a battery or a battery pack according to the present invention.

[Explanation of Codes] B, B'Battery packs E1, E2, E3 Electrodes 20 Discharge tank 21 Discharge liquid 22 Partition plates 30, 31, 43 Anion permeable membranes 32, 33, 40, 41, 42 Cation permeable membranes (4
0: 1 valent ion permeable membrane, 41: 2 valent ion permeable membrane) 34, 35, 36, 37, 44, 45, 46, 47 Bipolar membrane

Front page continuation (72) Inventor Tomiaki Furuya 8 Shinsita-cho, Isogo-ku, Yokohama-shi, Kanagawa Toshiba Yokohama Works (72) Inventor Katsumi Hayashi, Komukai-Toshiba-cho, Kawasaki-shi, Kanagawa Prefecture Toshiba Research Co., Ltd. In the development center (72) Inventor Motoo Yabuki 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Toshiba Research and Development Center (72) Inventor Masataka Onuma 1 Komukai-shiba-cho, Saiwai-ku, Kawasaki, Kanagawa Toshiba Research and Development Center (56) Reference JP-A-8-115752 (JP, A) JP-A-50-36378 (JP, A) JP-A-10-255861 (JP, A) JP-A-10-255862 ( JP, A) Japanese Patent Publication Sho 54-15273 (JP, B1) Chemical Society of Japan, Handbook of Chemistry, Applied Chemistry, I Process, Japan, Maruzen, October 15, 1986, p. 310 to 318 (58) Fields investigated (Int.Cl. ⁷ , DB name) H01M 10/54 H01M 6/52 B09B 1/00-5/00 C22B 1/00-61/00

Claims (10)

(57) [Claims] 1. A method for treating a battery having an electrode in which an active material is laminated on a current collector, wherein the electrode is mixed with hydrogen / argon.
Halogen is heated to 300-400 ° C in a mixed gas atmosphere.
A method for treating a battery, comprising: a heating step of decomposing a binder made of a resin containing the resin and joining the current collector of the electrode and the active material to separate the active material from the current collector. 2. A method of treating a battery having an electrode in which an active material is laminated on a current collector, wherein the battery is immersed in an aqueous sulfuric acid solution.
A discharging step of discharging the battery by
Dismantling process for dismantling and selecting electrodes from dismantled batteries
A separating step , an active material separating step of separating an active material from a current collector of the electrode, and a metal collecting step of recovering a metal component from the active material. A method for treating a battery, which comprises a heating step of heating in a reducing atmosphere to decompose a binder for joining the current collector and the active material. 3. An electrode having an active material laminated on a current collector
A method for treating a battery, comprising immersing the battery in an aqueous sulfuric acid solution.
A discharging step of discharging the battery by
Dismantling process for dismantling and selecting electrodes from dismantled batteries
And a separation step for separating the electrode into the current collector and the active material.
Active material separation process to separate and recover metal components from the active material
And a step of recovering the active material.
Characterized by having an acid treatment step of immersing the electrode in an acid solution
Battery treatment method. 4. A current collector of LiCoO ₂ and / or LiN
A method for treating a battery having an electrode in which an active material containing iO ₂ is laminated, comprising: an electrode separation step of separating the electrode from the battery; and an active material of separating the electrode into the current collector and the active material. A separation step, a metal recovery step of recovering a metal component from the active material, and a heavy liquid having a specific gravity of 1.9 to 2.9 g / ml were used.
The copper current collector and the aluminum contained in the current collector are selected by specific gravity selection.
And a step of separating the current collector made of minium ,
The method for treating a battery is characterized in that the quality separation step includes an acid treatment step of immersing the electrode in an acid solution. 5. The method for treating a battery according to claim 3 , wherein the acid solution is a 12 N or less aqueous sulfuric acid solution. 6. In the metal recovery step, the metal component of the active material is recovered from a solution in which the active material is dissolved in an acid solution, and in the metal recovery step, the metal component of the active material is recovered from the solution by electrodialysis. The method for treating a battery according to claim 2, further comprising an electrodialysis step of separating the cells. 7. A method for treating a battery having an electrode in which an active material is laminated on a current collector, wherein the battery is immersed in an aqueous sulfuric acid solution.
A discharging step of discharging the battery by
Dismantling process for dismantling and selecting electrodes from dismantled batteries
A step of separating, an active material separation step of separating the electrode into the current collector and the active material, and a metal recovery step of recovering a metal component of the active material from a solution in which the active material is dissolved in an acid solution. And the metal recovery step includes a hydrogen ion concentration adjusting step of adjusting a hydrogen ion concentration of the solution to precipitate a metal component of an active material from the solution, and an electrolysis step of electrolyzing the solution. Characteristic battery treatment method. 8. The current collector of LiCoO 2 _Two And / or LiN
iO _Two Battery Having Electrode Laminated With Active Material Containing
And heating the electrode in a reducing atmosphere.
And a binder for joining the current collector of the electrode and the active material
And a heating step of separating the active material from the current collector by decomposing the
Gravity selection using heavy liquid of 1.9-2.9 g / ml
Copper current collector and aluminum current collector included in the current collector
And a step of separating the body from the battery.
Processing method. 9. A current collector of LiCoO ₂ and / or LiN
Batteries having electrodes laminated with active material containing iO _2.
The method of treating, separating electrodes from batteries
And a step of separating the electrode into the current collector and the active material.
From the substance separation step and the solution in which the active material is dissolved in an acid solution,
A metal recovery step of recovering the metal component of the active material, and a specific gravity of 1.
The above-mentioned collection was carried out by specific gravity selection using a heavy liquid of 9 to 2.9 g / ml.
And a step of separating the copper current collector and A aluminum-made current collector included in the collector, the metal recovery step, the water of the solution
Adjust the concentration of elementary ions to remove the metal component of the active material from the solution.
Hydrogen ion concentration adjusting step for precipitation and electrolysis of the solution
Processing method that batteries be characterized as having a that electrolysis step. 10. A method for treating a battery, comprising a discharging step of discharging the battery by immersing the battery in a conductive liquid, wherein the conductive liquid is an aqueous sulfuric acid solution.