Method for preparing catalyst from negative electrode of ternary waste lithium battery

Abstract

The invention discloses a method for preparing a catalyst from a ternary lithium waste battery negative electrode. The method comprises the following steps: recovering graphite in the negative electrode from a ternary lithium battery; dispersing the recycled graphite in a glucose solution, adding rice hull-based white carbon black, and carefully stirring; and drying the product and carbonizing in an air atmosphere to obtain the granular catalyst. In the method disclosed by the invention, the dispersity of the recovered graphite is improved by adding the glucose; the dispersion process of the cobalt element in the graphite is completed through the repeated circulation process of the ternary lithium battery, so that the reutilization of solid wastes is realized; the rice hull-based white carbon black is used as a secondary load, so that the efficiency and the recoverability of the catalyst are improved.

Description

Technical Field

[0001] The present invention relates to the field of catalysts, and more specifically, to the preparation of an alcohol catalytic oxidation catalyst, and in particular to a method for preparing the catalyst from a negative electrode of a ternary lithium waste battery. Background Art

[0002] Cobalt oxides supported on carbon materials have the activity of catalyzing the selective oxidation of alcohols under mild conditions. (JagadeeshR V, Junge H, Pohl MM, et al. Selective oxidation of alcohols to esters using heterogeneous Co3O4-N@C catalysts under mild conditions. [J]. Journal of the American Chemical Society, 2013, 135 (29): 10776-82. DOI: 10.1021 / ja403615c.) Other studies have shown that amorphous cobalt elements highly dispersed in carbon materials also have certain alcohol catalytic oxidation activity. (Peng, Ling, Huo, et al. Highly efficient single atom cobalt catalyst for selective oxidation of alcohols [J]. Applied Catalysis, A. General: An International Journal Devoted to Catalytic Science and Its Applications, 2017, 543: 61-66.) In commercial ternary lithium-ion batteries, graphite is generally used as the corresponding negative electrode. After the ternary lithium battery reaches the end of its service life, graphite can be recovered from its negative electrode. The recovered graphite contains low-concentration and highly dispersed cobalt elements, and it is difficult to completely remove the cobalt elements without destroying the graphite structure. Rice husk-based white carbon black is a silicon dioxide with a multi-level pore structure obtained by ashing rice husks (Ouyang Dong, Chen Kai. Microstructure and chemical activity of low-temperature incinerated rice husk ash [J]. Journal of the Chinese Ceramic Society, 2003, 31 (11): 1121-1124.), which not only has excellent adsorption capacity, but is also relatively stable in a neutral environment and can be used as a catalyst carrier. Summary of the invention

[0003] Aiming at the problems of preparing alcohol catalyst under mild conditions and recycling negative electrode materials of ternary lithium ion batteries, the present invention aims to provide a method for preparing catalyst from the negative electrode of ternary lithium waste batteries.

[0004] The object of the present invention is achieved by the following scheme: A method for preparing a catalyst from a negative electrode of a ternary lithium waste battery comprises the following steps: (1) Recovering graphite from the negative electrode material of a ternary lithium-ion battery and preparing it into an aqueous dispersion to obtain a graphite dispersion; (2) adding glucose to the graphite dispersion obtained in step (1) to obtain graphite dispersion syrup; (3) adding rice husk-based silica to the graphite dispersion syrup obtained in step (2) and stirring thoroughly, wherein the ratio of recovered graphite to rice husk-based silica is 1:20 to 1:4; (4) The product obtained in step (3) is dried and then burned in an air atmosphere to obtain a catalyst.

[0005] Preferably, in step (4), the drying temperature is 80°C and the burning temperature is 350°C.

[0006] The addition of glucose improves the dispersibility of the recovered graphite. During the air burning process in step (4), the glucose gradually carbonizes and acts as a binder, reducing the peeling of the recovered graphite particles from the pores of the rice husk-based silica.

[0007] Under the above technical background, we have invented a method for preparing a catalyst from the negative electrode of a ternary lithium waste battery, aiming at the preparation of an alcohol catalyst under mild conditions and the recovery of the negative electrode material of a ternary lithium ion battery. The advantages of the present invention are as follows: (1) The dispersion of cobalt in graphite is completed through repeated cycles of ternary lithium batteries, thus achieving the recycling of solid waste.

[0008] (2) The use of rice husk-based silica as a secondary loading improves the efficiency and recyclability of the catalyst. DETAILED DESCRIPTION

[0009] The present invention will be further described below in conjunction with specific examples. The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial sources. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0010] Example 1 A catalyst is prepared from the negative electrode of a ternary lithium waste battery, wherein the ratio of recycled graphite to rice husk-based white carbon black is 1:20, and the preparation is carried out according to the following steps: (1) Recovering graphite from the negative electrode material of a ternary lithium-ion battery and preparing it into an aqueous dispersion to obtain a graphite dispersion; (2) adding glucose to the graphite dispersion obtained in step (1) to obtain graphite dispersion syrup; (3) adding rice husk-based silica to the graphite dispersion syrup obtained in step (2) and stirring thoroughly, wherein the ratio of recovered graphite to rice husk-based silica is 1:20 to 1:4; (4) The product obtained in step (3) is dried and then burned in an air atmosphere to obtain a catalyst.

[0011] (1) Recycling graphite from ternary lithium batteries The ternary lithium-ion battery was discharged at a constant current of 0.05C on a battery test bench, and the battery was disassembled in a dry environment to remove the negative electrode sheet; 20 g of the negative electrode sheet was washed once with 50 mL of N-methylformamide, immersed in 100 mL of pure water and ultrasonicated for 20 min to separate the negative electrode material from the copper foil matrix; the copper foil matrix was removed, and the recovered graphite was fully dispersed by rapid stirring at a constant temperature of 50°C for 4 h; after standing for 8 h, 80 mL of the solution on the top of the dispersion was sucked off to obtain a graphite dispersion, and the concentration of the remaining dispersion was determined by a gravimetric method; (2) Preparation of syrup dispersion for graphite recovery Weigh the graphite dispersion obtained in step (1), which contains 0.2 g of recovered graphite; add pure water to 10 mL, add 3 g of glucose and stir rapidly for 2 h to obtain a stable recovered graphite dispersion syrup, which is in the form of a viscous syrup; (3) Catalyst reloading Add 4 g of rice husk-based silica to the recovered graphite dispersion syrup obtained in step (2), and stir carefully with a glass rod for 0.5 h to obtain a black uniform slurry-like fluid; (4) Ashing reaction The product obtained in step (3) is placed on a multi-layer filter paper to absorb excess glucose solution; the product is dried at 80°C, placed in a quartz beaker, and heated to 350°C at a rate of 4°C / min in a muffle furnace, kept at this temperature for 2 h, and then cooled to room temperature to obtain a gray-black granular catalyst.

[0012] The cobalt content in this catalyst is about 0.05 mg / kg.

[0013] Example 2 A catalyst is prepared from the negative electrode of a ternary lithium waste battery, wherein the ratio of recycled graphite to rice husk-based white carbon black is 1:4, and the preparation is carried out according to the following steps: (1) Recycling graphite from ternary lithium batteries The ternary lithium-ion battery was discharged at a constant current of 0.05C on a battery test bench, and the battery was disassembled in a dry environment to remove the negative electrode sheet; 20 g of the negative electrode sheet was washed once with 50 mL of N-methylformamide, immersed in 100 mL of pure water and ultrasonicated for 20 min to separate the negative electrode material from the copper foil matrix; the copper foil matrix was removed, and the recovered graphite was fully dispersed by rapid stirring at a constant temperature of 50°C for 4 h; after standing for 8 h, 80 mL of the solution on the top of the dispersion was sucked off to obtain a graphite dispersion, and the concentration of the remaining dispersion was determined by a gravimetric method; (2) Preparation of syrup dispersion for graphite recovery Weigh the graphite dispersion obtained in step (1), which contains 1 g of recovered graphite; add pure water to 10 mL, add 3 g of glucose and stir rapidly for 2 h to obtain a stable recovered graphite dispersion syrup, which is in the form of a viscous syrup; (3) Catalyst reloading Add 4 g of rice husk-based silica to the recovered graphite dispersion syrup obtained in step (2), and stir carefully with a glass rod for 0.5 h to obtain a black uniform slurry-like fluid; (4) Ashing reaction The product obtained in step (3) is placed on a multi-layer filter paper to absorb excess glucose solution; the product is dried at 80°C, placed in a quartz beaker, and heated to 350°C at a rate of 4°C / min in a muffle furnace, kept at this temperature for 2 h, and then cooled to room temperature to obtain a gray-black granular catalyst.

[0014] The cobalt content in this catalyst is about 0.2 mg / kg.

[0015] The above embodiments are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A method for preparing a catalyst from a negative electrode of a ternary lithium waste battery, characterized in that: The steps include: (1) Recovering graphite from the negative electrode material of a ternary lithium-ion battery and preparing it into an aqueous dispersion to obtain a graphite dispersion; (2) adding glucose to the graphite dispersion obtained in step (1) to obtain graphite dispersion syrup; (3) adding rice husk-based silica to the graphite dispersion syrup obtained in step (2) and stirring thoroughly, wherein the ratio of recovered graphite to rice husk-based silica is 1:20 to 1:4; (4) The product obtained in step (3) is dried and then burned in an air atmosphere to obtain a catalyst.

2. A method for preparing a catalyst from a negative electrode of a ternary lithium waste battery according to claim 1, characterized in that: In step (4), the drying temperature is 80°C and the burning temperature is 350°C.

3. A method for preparing a catalyst from a negative electrode of a ternary lithium waste battery according to claim 1 or 2, characterized in that: The ratio of recycled graphite to rice husk-based white carbon black is 1:20, and the following steps are included: (1) Recycling graphite from ternary lithium batteries The ternary lithium-ion battery was completely discharged at a constant current of 0.05C on a battery test bench, the battery was disassembled in a dry environment, the negative electrode sheet was taken out, 20 g of the negative electrode sheet was washed once with 50 mL of N-methylformamide, immersed in 100 mL of pure water and ultrasonicated for 20 min to separate the negative electrode material from the copper foil matrix, the copper foil matrix was removed, and the recovered graphite was fully dispersed by rapid stirring at a constant temperature of 50 degrees Celsius for 4 h. After standing for 8 h, 80 mL of the solution on the top of the dispersion was sucked off to obtain a graphite dispersion, and the concentration of the obtained dispersion was determined by a gravimetric method; (2) Preparation of recycled graphite dispersion syrup Weigh the dispersion obtained in step (1), which contains 0.2 g of recovered graphite, add pure water to 10 mL, add 3 g of glucose and stir rapidly for 2 h to obtain a stable recovered graphite dispersion, and obtain a graphite dispersion syrup, which is in the form of a viscous syrup; (3) Catalyst reloading Add 4 g of rice husk-based silica to the graphite dispersion syrup obtained in step (2), and stir carefully with a glass rod for 0.5 h to obtain a black uniform slurry-like fluid; (4) Ashing reaction The product obtained in step (3) is placed on a multi-layer filter paper to absorb excess glucose solution, and the product is dried at 80°C. The product is placed in a quartz beaker and heated to 350°C at a rate of 4°C / min in a muffle furnace. After keeping the temperature for 2 h, the beaker is cooled to room temperature to obtain a gray-black granular catalyst.

4. A method for preparing a catalyst from a negative electrode of a ternary lithium waste battery according to claim 1 or 2, characterized in that: The ratio of recycled graphite to rice husk-based white carbon black is 1:4, and includes the following steps: (1) Recycling graphite from ternary lithium batteries The ternary lithium-ion battery was completely discharged at a constant current of 0.05C on a battery test bench, the battery was disassembled in a dry environment, the negative electrode sheet was taken out, 20 g of the negative electrode sheet was washed once with 50 mL of N-methylformamide, immersed in 100 mL of pure water and ultrasonicated for 20 min to separate the negative electrode material from the copper foil matrix, the copper foil matrix was removed, and the recovered graphite was fully dispersed by rapid stirring at a constant temperature of 50 degrees Celsius for 4 h. After standing for 8 h, 80 mL of the solution on the top of the dispersion was sucked off to obtain a graphite dispersion, and the concentration of the remaining graphite dispersion was determined by a gravimetric method; (2) Preparation of recycled graphite dispersion syrup Weigh the dispersion obtained in step (1), which contains 1 g of recovered graphite, add pure water to 10 mL, add 3 g of glucose and stir rapidly for 2 h to obtain a stable recovered graphite dispersion syrup, which is in the form of a viscous syrup; (3) Catalyst reloading Add 4 g of rice husk-based white carbon black to the recovered graphite dispersion syrup obtained in step (2), and stir carefully with a glass rod for 0.5 h to obtain a black uniform slurry-like fluid; (4) Ashing reaction The product obtained in step (3) is placed on a multi-layer filter paper to absorb excess glucose solution, and the product is dried at 80°C. The product is placed in a quartz beaker and heated to 350°C at a rate of 4°C / min in a muffle furnace. After keeping the temperature for 2 h, the beaker is cooled to room temperature to obtain a gray-black granular catalyst.