JP5535716B2 - Lithium recovery method - Google Patents

Description

  The present invention relates to a lithium recovery method capable of efficiently recovering lithium from lithium manganate, which is a positive electrode material of a lithium ion secondary battery.

Lithium-ion secondary batteries are secondary batteries that are lighter, have higher capacity, and have higher electromotive force than conventional lead-acid batteries, nickel-cadmium secondary batteries, etc., and are suitable for mobile devices such as mobile phones and laptop computers. Widely used.
As a positive electrode material of such a lithium ion secondary battery, lithium cobaltate (LiCoO ₂ ), lithium manganate (LiMn ₂ O ₄ ), and the like are used, and these include rare metals such as cobalt and lithium. include. Therefore, it is desired to recover these valuable substances from the used lithium ion secondary battery and to recycle them as a positive electrode material for the lithium ion secondary battery.

The lithium manganate is considered to have a stable structure called a spinel structure in which manganese and lithium atoms enter a gap between oxygen atoms. For example, a strong acid such as nitric acid, sulfuric acid, and hydrochloric acid is used. After dissolution, a neutralization reaction was performed to recover lithium and manganese (see Patent Document 1).
However, the recovery method requires a large amount of reducing agent in addition to the problem of low solubility in nitric acid and sulfuric acid. In addition, after lithium and manganese are dissolved, it is necessary to separate and recover lithium and manganese, which increases equipment. In addition, since hydrochloric acid, nitric acid, sulfuric acid used for dissolution, and caustic soda used for neutralization coexist, it is difficult to separate sodium and lithium. It is difficult. Further, when hydrochloric acid is used, there is a safety problem that harmful chlorine gas is generated.

In addition, for example, after adding a mineral acid such as nitric acid, hydrochloric acid, sulfuric acid or a mixture of mineral acid and hydrogen peroxide, the eluate is separated, and then the separated eluate is contacted with an organic solvent containing a metal extractant. Then, extraction separation treatment was performed, and a mineral acid was brought into contact with the organic solvent phase of the extract to carry out back extraction separation to recover lithium and manganese (see Patent Document 2).
However, the recovery method has a problem that, in addition to using mineral acid and hydrogen peroxide, a solvent extraction method in which the working environment is bad and safety management is difficult must be used.

JP-A-11-54159 JP-A-10-287864

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention does not require hydrogen peroxide, a mineral acid that requires wastewater treatment, and does not use a solvent extraction method in which the working environment is poor and safety management is difficult. An object of the present invention is to provide a method for recovering lithium that can efficiently recover lithium from lithium manganate and that can recycle lithium ion secondary batteries.

As a result of intensive studies by the present inventors in order to solve the above-mentioned problems, a mixture in which 1 part by mass or more of carbon is mixed with 100 parts by mass of lithium manganate having a stable spinel structure is oxidized in an air atmosphere. When roasted in any one of an atmosphere, an inert atmosphere, and a reducing atmosphere, lithium becomes lithium oxide (Li ₂ O). When the roasted material is leached with water, lithium hydroxide (LiOH) and lithium carbonate are leached. It was found that it was eluted as (Li ₂ CO ₃ ), and lithium could be recovered with extremely efficient and simple operation.

The present invention is based on the above findings by the present inventors, and means for solving the above problems are as follows. That is,
<1> A mixture in which 0.1 parts by mass or more of carbon is mixed with 100 parts by mass of lithium manganate is roasted in an air atmosphere, an oxidizing atmosphere, an inert atmosphere, or a reducing atmosphere. A method for recovering lithium, wherein the roasted product is leached with water.
<2> The lithium recovery method according to <1>, wherein 1 to 50 parts by mass of carbon is mixed with 100 parts by mass of lithium manganate.
<3> The leaching product obtained by roasting a mixture obtained by mixing 10 parts by mass to 50 parts by mass of carbon with 100 parts by mass of lithium manganate at a temperature of 400 ° C. or higher in an air atmosphere with water. <1> to <2> The method for recovering lithium according to any one of <2>.
<4> A mixture obtained by mixing 3 parts by mass to 50 parts by mass of carbon with respect to 100 parts by mass of lithium manganate is leached with water in an inert atmosphere at a temperature of 600 ° C. or higher. The lithium recovery method according to any one of <1> to <2>.
<5> The leaching product obtained by roasting a mixture obtained by mixing 5 to 50 parts by mass of carbon with respect to 100 parts by mass of lithium manganate at a temperature of 400 ° C. or higher in an oxidizing atmosphere with water. <1> to <2> The method for recovering lithium according to any one of <2>.
<6> When the oxygen concentration in the atmosphere when roasting a mixture of carbon and lithium manganate is X, and Y is the amount of carbon mixed with respect to 100 parts by mass of lithium manganate, Y> 0. The lithium recovery method according to any one of <1> to <5>, wherein 3283X + 3.1551 is satisfied.
<7> The lithium recovery method according to any one of <1> to <6>, wherein the mixture obtained by mixing lithium manganate and carbon is obtained from a used lithium ion secondary battery.
<8> The above <1>, wherein the carbon is obtained from any one of carbon black, graphite, activated carbon, coal, coke, charcoal, a negative electrode of a used lithium ion secondary battery, and a reducing organic substance. To <7>. The method for recovering lithium according to any one of <7>.

  According to the present invention, conventional problems can be solved, hydrogen peroxide, mineral acids that require wastewater treatment are not required, and solvent extraction methods that are difficult to perform safety management are difficult without using a working environment. In addition, it is possible to provide a lithium recovery method that can efficiently recover lithium from lithium manganate that is a positive electrode material of a lithium ion secondary battery, and that can recycle the lithium ion secondary battery.

FIG. 1 is a graph showing the relationship between the oxygen concentration X in the atmosphere when roasting a mixture of lithium manganate and carbon in Examples and the amount Y of carbon mixed with 100 parts by mass of lithium manganate. .

The method for recovering lithium according to the present invention includes a roasted product obtained by roasting a mixture of lithium manganate and carbon in an air atmosphere, an oxidizing atmosphere, an inert atmosphere, or a reducing atmosphere. It is leached with water.
The mixture of lithium manganate and carbon includes, in addition to the mixture of lithium manganate and carbon separately, those containing lithium manganate and carbon together, such as pulverized lithium ion secondary batteries. It is.

-Lithium manganate-
The lithium manganate is not particularly limited as long as it contains a certain amount or more of lithium manganate (LiMn ₂ O ₄ ), and can be appropriately selected according to the purpose. Products, positive electrode waste materials of used lithium ion secondary batteries, lithium manganate separated from positive electrode waste materials of used lithium ion secondary batteries, and positive electrode waste materials formed of manganese, nickel, cobalt, and lithium. Among these, a positive electrode waste material of a used lithium ion secondary battery is particularly preferable from the viewpoint that the lithium ion secondary battery can be recycled.

-Carbon-
The carbon is not particularly limited and may be appropriately selected depending on the intended purpose. For example, carbon black, graphite, activated carbon, coal, coke, charcoal, a negative electrode of a used lithium ion secondary battery, an organic substance having reducibility Etc. Among these, the negative electrode of the used lithium ion secondary battery is particularly preferable because the lithium ion secondary battery can be recycled.
Examples of the organic substance having reducibility include propylene carbonate and ethylene carbonate, which are electrolyte materials, and polyolefin films, which are separator materials.

The method of mixing the carbon and the lithium manganate is not particularly limited and can be appropriately selected according to the purpose. For example, when only the positive electrode material of the lithium ion secondary battery is taken out, the positive electrode material and the carbon are mixed. There is a method of mixing with a mixer.
The mixer is not particularly limited and can be appropriately selected according to the purpose. For example, a V-type blender, a rotary mixer, a line mixer, etc. can be used, and using a furnace having mixing performance such as a rotary kiln, Mixing and roasting may be performed simultaneously.
In addition, since carbon (graphite) is contained in the negative electrode of the lithium ion secondary battery, the addition of carbon is not necessary when the product obtained from the lithium ion secondary battery is roasted.

  The mixing amount of carbon is 1 part by mass or more with respect to 100 parts by mass of lithium manganate, and preferably 1 part by mass to 50 parts by mass. When the mixing amount of the carbon is less than 1 part by mass, for example, the crystal structure of the positive electrode of the lithium ion secondary battery cannot be destroyed, so that lithium may not be eluted, and when it exceeds 50 parts by mass, the lithium manganate Since the carbon component remains after roasting the mixture of carbon and carbon, a carbon removal step may be required.

As a mixture of the lithium manganate and carbon, it is typically preferable to use a mixture obtained from a used lithium ion secondary battery.
This is a mixture of lithium manganate and carbon, and when using one obtained from a used lithium ion secondary battery, without performing a special pretreatment (separation treatment of lithium manganate) This is preferable because lithium can be recovered.
In addition, when a mixture obtained from a used lithium ion secondary battery is used as the mixture of lithium manganate and carbon, graphite (carbon) is manganic acid on the negative electrode of the used lithium ion secondary battery. Since it is contained in a maximum amount of 40% by mass with respect to lithium, it is particularly preferable in that it is not necessary to add carbon and can be roasted as it is.
Further, although a discharge process is required for normal cathode separation, the discharge can be performed by roasting the lithium ion secondary battery, which is excellent in that it is not necessary to provide a discharge facility.
The used lithium ion secondary battery may be pulverized before roasting, and the order of pulverization is not particularly limited.
There is no restriction | limiting in particular as a method of grind | pulverizing a used lithium ion secondary battery, According to the objective, it can select suitably, For example, a hammer crusher, a rod mill, a ball mill, a jaw crusher, a roll crusher, a cutter mill, a rotary crusher etc. A pulverized product obtained by sieving with a pulverizer can be used.

-Atmosphere used for roasting-
There is no restriction | limiting in particular as atmosphere used for the said baking, According to baking conditions etc., it can select suitably, For example, an air atmosphere, an oxidizing atmosphere, an inert atmosphere, a reducing atmosphere etc. are mentioned. The atmosphere is preferably aerated during roasting.
Here, the air atmosphere means an atmosphere using air (air) of 21% oxygen and 78% nitrogen.
The oxidizing atmosphere means an atmosphere containing 1% by mass to 21% by mass of oxygen in an inert atmosphere such as nitrogen or argon, and an atmosphere containing 1% by mass to 5% by mass of oxygen is preferable.
The inert atmosphere means an atmosphere made of nitrogen or argon.
The reducing atmosphere means an atmosphere containing CO, H ₂ , H ₂ S, SO ₂ and the like in an inert atmosphere such as nitrogen or argon.

-Roasting-
The roasting is preferably performed using a roasting furnace. There is no restriction | limiting in particular as said roasting furnace, According to the objective, it can select suitably, For example, batch type furnaces, such as a rotary kiln, a fluidized bed furnace, a tunnel furnace, a muffle, a cupola, a stalker furnace, etc. are mentioned. In the present invention, since roasting can be performed even in an air atmosphere, a commonly used roasting furnace such as a rotary kiln furnace can be used, and the selection range of the roasting furnace is widened.
The roasting temperature is not particularly limited and may be appropriately selected according to the purpose. The roasting temperature is 400 ° C. or higher in an air atmosphere, 600 ° C. or higher in an inert atmosphere, and 400 ° C. or higher in an oxidizing atmosphere. The upper limit temperature is preferably 1,200 ° C. or lower.
If the roasting temperature is less than 400 ° C., for example, the crystal structure of the positive electrode of the lithium ion secondary battery cannot be destroyed, so lithium may not be eluted. In addition, since the roasted product is sintered, a pulverization step may be required.

-Lithium leaching-
By leaching the obtained roasted product with water, lithium can be eluted from the roasted product and lithium can be recovered.
The method for leaching the roasted product with water is not particularly limited and can be appropriately selected according to the purpose. For example, the roasted product immersed in water is gently stirred while applying ultrasonic waves as necessary. This can be done.
The liquid from which lithium is eluted by leaching is filtered and separated into a residue and a filtrate, and lithium can be recovered from the filtrate. The recovery method is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method of naturally drying the filtrate, a method of drying and solidifying by heating, and a method of crystallizing while blowing carbonic acid. .

  In the method for recovering lithium according to the present invention, any one of the following first to third embodiments is preferable depending on roasting conditions.

<First Embodiment>
In the lithium recovery method of the first embodiment, a mixture obtained by mixing 10 parts by mass to 50 parts by mass of carbon with respect to 100 parts by mass of lithium manganate is roasted at a temperature of 400 ° C. or higher in an air atmosphere. This is a mode in which the roasted product is leached with water.
The amount of carbon mixed is preferably 10 parts by mass to 50 parts by mass, and more preferably 20 parts by mass to 30 parts by mass with respect to 100 parts by mass of lithium manganate.
In the first embodiment, since roasting can be performed in an air atmosphere, a commonly used roasting furnace such as a rotary kiln furnace can be used.
The roasting temperature is preferably 400 ° C. or higher, and more preferably 700 ° C. to 1,000 ° C. When the roasting temperature is lower than 400 ° C., for example, the crystal structure of the positive electrode of the lithium ion secondary battery cannot be destroyed, and thus lithium cannot be eluted.
The roasting time is preferably 1 hour or more including the temperature rising time, and the elution effect does not change greatly even if the time is long. Therefore, 1 hour to 2 hours is more preferable from the viewpoint of energy saving.

<Second Embodiment>
In the lithium recovery method of the second embodiment, a mixture obtained by mixing 3 parts by mass to 50 parts by mass of carbon with respect to 100 parts by mass of lithium manganate is roasted at a temperature of 600 ° C. or higher in an inert atmosphere. This is a mode of leaching the roasted product obtained with water.
The mixing amount of carbon is preferably 3 parts by mass to 50 parts by mass, and more preferably 10 parts by mass to 40 parts by mass with respect to 100 parts by mass of lithium manganate.
The roasting temperature is preferably 600 ° C. or higher, and more preferably 700 ° C. to 1,000 ° C. When the roasting temperature is lower than 600 ° C., for example, the crystal structure of the positive electrode of the lithium ion secondary battery cannot be destroyed, so that lithium may not be eluted.
The roasting time is preferably 1 hour or more including the temperature rising time, and the elution effect does not change greatly even if the time is long. Therefore, 1 hour to 2 hours is more preferable from the viewpoint of energy saving.

<Third Embodiment>
In the method for recovering lithium according to the third embodiment, a mixture in which 5 to 50 parts by mass of carbon is mixed with 100 parts by mass of lithium manganate is roasted at a temperature of 400 ° C. or higher in an oxidizing atmosphere. This is a mode in which the roasted product is leached with water.
The mixing amount of carbon is preferably 5 parts by mass to 50 parts by mass and more preferably 5 parts by mass to 40 parts by mass with respect to 100 parts by mass of lithium manganate.
The roasting temperature is preferably 400 ° C. or higher, and more preferably 700 ° C. to 1,000 ° C. When the roasting temperature is lower than 400 ° C., for example, the crystal structure of the positive electrode of the lithium ion secondary battery cannot be destroyed, and thus lithium cannot be eluted.
The roasting time is preferably 1 hour or more including the temperature rising time, and the elution effect does not change greatly even if the time is long. Therefore, 1 hour to 2 hours is more preferable from the viewpoint of energy saving.

  In the present invention, when the oxygen concentration (mass%) in the atmosphere at the time of roasting the mixture of lithium manganate and carbon is X, and the carbon mixing amount with respect to 100 parts by mass of lithium manganate is Y, the following formula: It is preferable to satisfy Y> 0.3283X + 1.551. In this range, the lithium leaching rate can be 1% or more.

The lithium recovery method of the present invention can efficiently recover lithium from lithium manganate, which is a positive electrode material of a lithium ion secondary battery, and can recycle the lithium ion secondary battery.
In the method for recovering lithium according to the present invention, the product obtained from the lithium ion secondary battery can be pulverized and roasted as it is without performing any special pretreatment (separation treatment of lithium manganate). Lithium can be recovered.
The lithium recovery method of the present invention has the advantage that the generation of carbon residue is small and the amount of energy used is small, especially when roasting in an oxidizing atmosphere.
In the lithium recovery method of the present invention, lithium and manganese can be separated to a high degree by simple operations such that manganese is not detected in the lithium recovery. Therefore, the recovered lithium can be reused not only for lithium manganate but also for other lithium-containing compounds such as lithium cobaltate. In addition, the step of separating and recovering lithium and manganese, which is necessary for the conventional lithium recovery method, is not required, and the recovery process can be shortened and the recovery cost can be reduced as compared with the conventional lithium recovery method.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
-Separation of lithium battery positive electrode material-
A commercially available lithium ion secondary battery (manufactured by AU, using lithium manganate for the positive electrode, graphite for the negative electrode, carbon content of 40% by mass with respect to lithium manganate) is immersed in an electrolytic solution (5% NaCl). Then, it was discharged until it became 0.1 mV. Thereafter, the positive electrode material was taken out by manual decomposition and pulverized using a cutter mill to obtain a positive electrode material powder. The composition is shown in Table 1. As a result of analysis, it was confirmed that the separated powder was lithium manganate.

-Roasting of lithium manganate-
Carbon black (manufactured by Wako Pure Chemical Industries, Ltd.) was added to 10 g of the obtained lithium manganate so that the carbon concentration (mass%) relative to the lithium manganate is shown in Table 2, and a tubular furnace (manufactured by KOYO LINDBERG) ). As the atmosphere, roasting was performed while passing an inert atmosphere (nitrogen) of 5 L / min shown in Table 2. The roasting time was 1 hour after reaching the temperatures shown in Table 2.
About each obtained roasted material, the composition was analyzed as follows.

<Analysis of Lithium and Manganese in Roasted Products (Solids)>
0.1 g of each baked product was dissolved by heating in aqua regia until immediately before drying, and after filtration, it was made up to 100 mL with ion-exchanged water to obtain a solution for analysis. The solution was analyzed by a high-frequency plasma emission spectroscopic analyzer (manufactured by Nippon Jarrel Ash Co., Ltd., ICAP-575II), and the lithium concentration and manganese concentration in the roasted product (solid material) were calculated.

<Lithium leaching operation>
0.5 g of each of the obtained roasted products was placed in a 100 mL volumetric flask, water was made up to 100 mL, transferred to a beaker, and then lithium was eluted for 30 minutes while gently stirring while applying ultrasonic waves. . The liquid was filtered and divided into a residue and a filtrate, and each was analyzed. The residue was analyzed by the above-described method, and the filtrate was directly analyzed by a high-frequency plasma emission spectroscopic analyzer (manufactured by Nippon Jarrell-Ash, ICAP-575II).

  The leaching rate of lithium and the leaching rate of manganese were calculated from the lithium content and manganese content in the roasted product (solid), and the lithium amount and manganese amount dissolved in the filtrate. The results are shown in Table 2.

In addition, “<0.01” of the Mn leaching rate was that the leaching rate of manganese was less than 0.01%, specifically, the lower limit of detection (3.46 × 10 ⁻⁵ %) or less. Indicates.

(Example 2)
In Example 1, as the oxidizing atmosphere, oxygen and nitrogen were vented at a total of 5 L / min so as to have an oxygen concentration (mass%) and a nitrogen concentration (mass%) shown in Table 3, and the roasting shown in Table 3 was performed. Each roast was obtained in the same manner as in Example 1 except that the baking was performed at the baking temperature.
About each obtained roasted material, it carried out similarly to Example 1, and calculated | required Li leaching rate and Mn leaching rate. The results are shown in Table 3.

In addition, “<0.01” of the Mn leaching rate was that the leaching rate of manganese was less than 0.01%, specifically, the lower limit of detection (3.46 × 10 ⁻⁵ %) or less. Indicates.

(Example 3)
In Example 1, as the oxidizing atmosphere, oxygen and nitrogen were vented at a total rate of 5 L / min so as to be the oxygen concentration (mass%) and nitrogen concentration (mass%) shown in Table 4, and the roasting shown in Table 4 was performed. Each roast was obtained in the same manner as in Example 1 except that the baking was performed at the baking temperature.
About each obtained roasted material, it carried out similarly to Example 1, and calculated | required Li leaching rate and Mn leaching rate. The results are shown in Table 4.

In addition, “<0.01” of the Mn leaching rate was that the leaching rate of manganese was less than 0.01%, specifically, the lower limit of detection (3.46 × 10 ⁻⁵ %) or less. Indicates.

Example 4
In Example 1, each was performed in the same manner as in Example 1 except that the air was baked at the roasting temperature shown in Table 5 while ventilating the air atmosphere (21% oxygen, 78% nitrogen) at 5 L / min. A roasted product was obtained.
About each obtained roasted material, it carried out similarly to Example 1, and calculated | required Li leaching rate and Mn leaching rate. The results are shown in Table 5.

In addition, “<0.01” of the Mn leaching rate was that the leaching rate of manganese was less than 0.01%, specifically, the lower limit of detection (3.46 × 10 ⁻⁵ %) or less. Indicates.

Of the results shown in Tables 2 to 5, data for roasting temperature of 600 ° C. or higher and lithium leaching rate of 1% or higher is plotted, and the oxygen concentration (mass) in the atmosphere when roasting lithium manganate is plotted. %) The relationship between X and the mixing amount Y of carbon with respect to 100 parts by mass of lithium manganate was determined. The results are shown in FIG.
From the result of FIG. 1, it was found that the lithium leaching rate was 1% or more satisfying the following formula, Y> 0.3283X + 1.551.

(Example 5)
A commercially available used lithium ion secondary battery (lithium manganate for the positive electrode, graphite for the negative electrode, the carbon content with respect to lithium manganate is 40% by mass) as it is under atmospheric air (21% oxygen, 78% nitrogen), It inserted in the tubular furnace (made by KOYO LINDBERG) at 850 degreeC, and baked for 1.5 hours. The battery weight before heating was 301 g, and the battery weight after heating was 216 g.
The obtained baked product was pulverized by a cutter mill to remove a large metal portion that was visible. The total amount of powder obtained by pulverization was 132 g, and the removed metal portion was 84 g. The composition of the obtained powder was analyzed in the same manner as in Example 1. As a result, Li was 2.3% by mass and Mn was 36% by mass.
Next, the obtained powder was leached and analyzed in the same manner as in Example 1. As a result, the leaching rate of Li was 63%, and the leaching rate of Mn was 0.01% or less (more specifically, the detection lower limit). Value (3.46 × 10 ⁻⁵ %) or less).

(Example 6)
Using the same used lithium ion secondary battery as in Example 5, the roasting temperature was set to 700 ° C. in the same manner as in Example 5 while aerating the air atmosphere (21% oxygen, 78% nitrogen) at 5 L / min. The carbon content with respect to lithium manganate was 30% by mass, and roasting was performed without providing a holding time. As a result of analyzing the obtained roasted product by the same method as in Example 1, the Li leaching rate was 60%, and no change in the Li leaching rate was maintained.

  The lithium recovery method of the present invention can efficiently recover lithium from lithium manganate, which is a positive electrode material of a lithium ion secondary battery, and can reuse the lithium ion secondary battery.

Claims (8)

  A roasted product obtained by roasting a mixture in which 1 part by mass or more of carbon is mixed with 100 parts by mass of lithium manganate in an air atmosphere, an oxidizing atmosphere, an inert atmosphere, or a reducing atmosphere. Lithium recovery method characterized by leaching with water.   The method for recovering lithium according to claim 1, wherein 1 to 50 parts by mass of carbon is mixed with 100 parts by mass of lithium manganate. A baked product obtained by roasting a mixture obtained by mixing 10 parts by mass to 50 parts by mass of carbon with respect to 100 parts by mass of lithium manganate at a temperature of 400 ° C. or higher in an air atmosphere is leached with water. 3. The method for recovering lithium according to any one of 2 above. A baked product obtained by roasting a mixture obtained by mixing 3 to 50 parts by mass of carbon with 100 parts by mass of lithium manganate at a temperature of 600 ° C or higher in an inert atmosphere is leached with water. 3. The method for recovering lithium according to any one of items 1 to 2. A baked product obtained by roasting a mixture obtained by mixing 5 to 50 parts by mass of carbon with respect to 100 parts by mass of lithium manganate at a temperature of 400 ° C or higher in an oxidizing atmosphere is leached with water. 3. The method for recovering lithium according to any one of 2 above. Assuming that the oxygen concentration in the atmosphere when roasting a mixture of lithium manganate and carbon is X, and Y is the amount of carbon mixed with respect to 100 parts by mass of lithium manganate, Y> 0.3283X + 1.551 The method for recovering lithium according to any one of claims 1 to 5, wherein: The method for recovering lithium according to any one of claims 1 to 6, wherein the mixture obtained by mixing lithium manganate and carbon is obtained from a used lithium ion secondary battery. Any carbon, carbon black, graphite, activated carbon, coal, coke, charcoal, claims 1 negative electrode, and is obtained more or organic substances having a reducing already lithium ion secondary battery using 7 The method for recovering lithium according to claim 1 .