Method for preparing ternary sulfide catalyst by using waste batteries and application of ternary sulfide catalyst

Abstract

The invention discloses a method for preparing a ternary sulfide catalyst by utilizing a waste battery and application of the ternary sulfide catalyst. The method comprises the following steps: S1, separating and collecting a positive electrode material; s2, preparing an electro-deposition leaching solution; s3, a layered NiCoMn (OH) x / NF precursor is prepared through primary electro-deposition; s4, a NiCoMnS < x > / NF catalyst is prepared through secondary electro-deposition; the catalyst is applied to an electro-catalysis hydrogen evolution reaction and a sulfur ion oxidation reaction. The method is simple in process, controllable in cost and free of toxic gas generation, and the catalyst is excellent in performance, so that the catalyst shows extremely high applicability and popularization value in industrial production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrocatalytic material preparation, in particular to a method for preparing ternary sulfide catalysts from waste batteries and applications thereof. BACKGROUND

[0002] Ternary lithium batteries are the core energy storage devices for new energy vehicles, consumer electronics and energy storage power stations. Their service life is affected by charging and discharging strategies, environmental temperature and humidity, etc. and is usually 3-5 years. After 1000-2000 cycles of lithium ion intercalation and deintercalation, irreversible degradation occurs inside the battery: the layered structure of the positive electrode lithium nickel cobalt manganese oxide (NCM) collapses, and nickel and cobalt ions dissolve and migrate; the graphite matrix of the negative electrode is repeatedly expanded and pulverized, and the surface solid electrolyte interface film is thickened, resulting in a sharp increase in lithium ion transmission impedance, and ultimately the battery loses its value and enters the scrap stage. However, waste ternary lithium batteries have both environmental risks and resource values, containing valuable metals such as cobalt (15%-20%) and nickel (10%-15%), as well as fluorine-containing components such as carbonate electrolyte and polyvinylidene fluoride (PVDF). Improper disposal can cause multi-medium pollution, inhibit microbial activity, induce acidification, form a synergistic toxicity system in water, and be enriched through the food chain. However, the valuable metals such as nickel, cobalt, lithium and manganese contained in the battery make it a valuable "urban mine", so the efficient recovery and resource utilization of high-value metals from retired ternary lithium batteries are becoming increasingly prominent, and have become a key factor in promoting the high-quality upgrading and sustainable development of the industry.

[0003] Pyrometallurgy and hydrometallurgy are traditional core technologies for the resource utilization of waste lithium batteries. Although they have achieved large-scale application of tens of thousands of tons, they are still trapped in the "resource utilization-secondary pollution" dilemma. Pyrometallurgy relies on high-temperature pyrolysis-reduction smelting, which has very high energy consumption and releases highly toxic gases such as HF and CF4, with a cobalt and nickel recovery rate of less than 90%. Hydrometallurgy is subject to the long process of "acid leaching-impurity removal-multi-stage extraction", which results in large consumption of extractants and the generation of high-salinity acidic wastewater, with subsequent treatment costs accounting for more than 30%. With the intensification of the "retirement wave" of batteries, it is urgent to develop a green resource utilization path with low energy consumption and low pollution.

[0004] Currently, the hydrometallurgical leaching technology centered on green acid leaching has achieved a breakthrough: through the optimization of acid-assisted leaching agents, the process has been shortened by more than 40%, the energy consumption has been reduced by 30% compared to traditional hydrometallurgy, the leaching rates of nickel, cobalt and manganese have stabilized at more than 95%, and the pain points of traditional processes have been avoided. The valuable metals recovered are converted into hydrogen production catalysts for electrolytic water, further establishing a cross-disciplinary synergy paradigm for "retired batteries-hydrogen energy" industry.

[0005] Electrolysis of water to produce hydrogen is key to breaking the dependence on fossil fuels and supporting the "dual carbon" goal. The core of this process is the electrochemical coupling of the oxygen evolution reaction (OER) at the anolyte and the hydrogen evolution reaction (HER) at the cathode. However, the slow four-electron transfer kinetics of the OER and its high overpotential lead to high energy consumption, hindering large-scale application. Therefore, a route using a low-potential sulfide ion oxidation reaction (SOR) to replace the OER has emerged, leveraging the S... 2- / S n 2- The thermodynamic advantages of oxidation, theoretically reducing the cell voltage by 0.5-0.8V, enable synergistic effects of hydrogen production and sulfur-containing wastewater treatment. This technological breakthrough relies on the development of HER / SOR bifunctional catalysts. While platinum group metal-based catalysts can significantly reduce overpotential and exhibit excellent performance, their extremely low abundance in the Earth's crust and uneven geographical distribution create a cost barrier for large-scale production. Therefore, developing low-cost non-precious metal-based bifunctional catalysts based on recycled metals from retired batteries has become a key approach, but it faces the following three challenges: (1) Green leaching control process: It is necessary to develop a low acid consumption process to achieve a metal selective leaching rate of ≥98% for waste ternary lithium-ion batteries; (2) Directional construction of catalysts: It is necessary to achieve synergistic catalysis of HER and SOR by controlling the crystal phase, morphology and microstructure; (3) Industrialization adaptation: A simple and green synthesis route should be constructed to achieve the control of morphological composition uniformity and performance stability during the large-scale preparation of catalysts, and finally achieve efficient adaptation to the industrial production system. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a method for preparing ternary sulfide catalysts using waste batteries and its application.

[0007] The technical solution of this invention is: A method for preparing ternary sulfide catalysts using waste batteries includes the following steps: S1. Separation and collection of positive electrode materials: waste ternary nickel cobalt manganese lithium batteries are discharged, disassembled and classified in sequence to obtain positive electrode materials. The positive electrode materials are ultrasonically cleaned to remove the nickel cobalt manganese lithium oxide coating. The removed nickel cobalt manganese lithium oxide coating is centrifuged to obtain nickel cobalt manganese lithium oxide active powder. S2. Preparation of electrodeposition leachate: The lithium nickel cobalt manganese oxide active powder obtained in S1 is added to hydrochloric acid solution. The ratio of lithium nickel cobalt manganese oxide active powder to hydrochloric acid solution is 5~15 mmol: 20 mL. After stirring, a mixture is obtained. The mixture is filtered to obtain a leachate containing metal ions. S3. Preparation of layered NiCoMn(OH) by single electrodeposition x / NF precursor: the leaching solution obtained in S2 is adjusted to pH 5-7 as the electrolyte for primary electrodeposition, the bulk foam nickel is pretreated with a hydrochloric acid solution to obtain / NF as the working electrode for primary electrodeposition, Ag / AgCl is taken as the reference electrode for primary electrodeposition, and Pt is taken as the counter electrode for primary electrodeposition, and the primary electrodeposition of metal ions is carried out under constant voltage, and after the reaction is completed, the obtained solid material is cooled, washed and dried to obtain layered NiCoMn(OH) x / NF precursor; S4, preparation of NiCoMnS by secondary electrodeposition x / NF catalyst: a mixed solution of NaOH and Na2S is taken as the electrolyte for secondary electrodeposition, the layered NiCoMn(OH) x / NF precursor obtained in S3 is taken as the working electrode for secondary electrodeposition, Ag / AgCl is taken as the reference electrode for secondary electrodeposition, and Pt is taken as the counter electrode for secondary electrodeposition, and the secondary electrodeposition is carried out under constant current, and after the reaction is completed, the obtained solid material is cooled, washed and dried to obtain a ternary sulfide NiCoMnSx / NF catalyst.

[0008] Further, the waste and old ternary lithium nickel-cobalt-manganese acid battery is LiNi 0.33 Co 0.33 Mn 0.33 O2, LiNi 0.5 Co 0.2 Mn 0.3 O2, LiNi 0.6 Co 0.2 Mn 0.2 O2, LiNi 0.8 Co 0.1 Mn 0.1 O2.

[0009] Note: The selected waste and old ternary lithium nickel-cobalt-manganese acid battery contains the metal elements required in the catalyst.

[0010] Further, in S1, the ultrasonic power during ultrasonic cleaning is 180-240 W, the ultrasonic cleaning time is 3-6 h, the centrifugal separation speed is 800-1200 rpm, and the centrifugal separation time is 3-6 min.

[0011] Note: By reasonably controlling the parameters of ultrasonic cleaning and centrifugal separation, the cleaning and separation are ensured to be thorough.

[0012] Further, in S2, the molar concentration of the hydrochloric acid solution is 1-6 mol / L, the stirring mode is magnetic stirring on a magnetic stirrer, and the stirring time is 19-28 h.

[0013] Description: By selecting hydrochloric acid as the leaching agent, metal ion leaching is studied, and the concentration of nitric acid and stirring time are systematically controlled to realize efficient dissolution of cobalt ions, nickel ions, manganese ions and lithium ions, and obtain target leaching solution with high leaching rate.

[0014] Further, in S3, the molar concentration of NaOH solution used when adjusting the pH of the leaching solution is 1-3 mol / L, the voltage of the first electrodeposition is-1.5 to-0.5 V (vs. Ag / AgCl), the deposition time is 10-60 min, and when the solid substance is cleaned and dried, it is cleaned with distilled water and anhydrous ethanol for 3 times respectively, and then dried in a vacuum oven at 45-55 DEG C for 1-2 h for use.

[0015] Description: By reasonably controlling the parameters of the first electrodeposition to balance the deposition rate of the first electrodeposition, the NiCoMn(OH) x / NF precursor with nanosheet layer assembled spherical structure is successfully synthesized on the surface of the foamed nickel (NF) Further, in S3, the size of the blocky foamed nickel is 1-2 cm x 1-2 cm, and the method for pretreating the blocky foamed nickel with hydrochloric acid solution is: ultrasonic treatment of the blocky foamed nickel in a hydrochloric acid solution with a molar concentration of 3-5 mol / L for 20-30 min to remove the oxides and impurities on the surface, and then cleaned with distilled water and anhydrous ethanol for 3 times respectively, and then dried in a vacuum oven at 45-55 DEG C for 1-2 h for use.

[0016] Description: The oxides and impurities on the surface of the blocky foamed nickel are removed by pretreating the blocky foamed nickel with hydrochloric acid.

[0017] Further, in S4, the molar concentration of NaOH in the electrolyte of the second electrodeposition is 1-3 mol / L, the molar concentration of Na2S is 1-3 mol / L, the volume ratio of the electrolyte of the first electrodeposition to the electrolyte of the second electrodeposition is 40-65:30-70, the current of the second electrodeposition process is 0.05-1.0 A, the deposition time is 10-70 min, and when the solid substance is cooled and cleaned and dried, it is cleaned with distilled water and anhydrous ethanol for 3 times respectively, and then dried in a vacuum oven at 45-55 DEG C for 1-2 h for use.

[0018] Description: By reasonably controlling the parameters of the second electrodeposition and the electrolyte ratio of the two electrodepositions, a suitable deposition rate is ensured, and a deposition layer with good quality is obtained.

[0019] The application also provides a ternary sulfide catalyst, which is prepared by the method of any one of the above methods, and is applied in electrocatalytic hydrogen evolution reaction and sulfur ion oxidation reaction.

[0020] The beneficial effects of the present application are: (1) The present application provides a method for preparing ternary sulfide catalysts from waste batteries. The final product NiCoMnS x / NF catalyst is composed of a nickel foam ( / NF) matrix and NiCoMnS x / NF active components distributed on the / NF matrix. The Ni, Co, and Mn metal components contained therein are valuable metal resources recovered from waste lithium nickel cobalt manganese batteries through directional separation, and the morphological characteristics of the layered NiCoMn(OH) x / NF precursor are completely retained, and the microstructure exhibits a large number of two-dimensional layered structure units that are self-assembled to form nanoscale spherical aggregates with clear hierarchical characteristics. The two-step electrodeposition method provides an efficient path for the preparation of NiCoMnS x / NF catalyst. The entire method is simple, cost-controllable, and generates no toxic gases. In addition, the catalyst itself has excellent performance, making it highly suitable for industrial production and has strong promotional value.

[0021] (2) The method of the present application selects appropriate leaching agents for metal ion leaching research. By systematically controlling the concentration of the leaching agent and the stirring time, efficient dissolution of cobalt ions, nickel ions, manganese ions, and lithium ions is achieved, and a target leaching solution with high leaching rate is obtained. At the same time, this process path can avoid the generation of toxic gases and has low energy consumption characteristics, meeting the basic needs of green environmental protection and industrial application.

[0022] (3) The method of the present application controls the nucleation and growth process of metal ions through a one-step electrodeposition process, successfully synthesizing a NiCoMn(OH) x / NF precursor with a nanosheet layer assembly spherical structure on the surface of the nickel foam (NF). Further, the precursor is in-situ topologically sulfurized to obtain a NiCoMnS x / NF catalyst. The sulfurized product completely inherits the multi-level spherical structure of the precursor, which provides a spatial basis for the full exposure of active sites, ultimately achieving a synergistic improvement in HER and SOR electrocatalytic activity.

[0023] (4) The method of the present application converts the crystalline NiCoMn(OH) x / NF into amorphous NiCoMnS x / NF catalyst after in-situ topological sulfurization with Na2S. This amorphization effect is due to the replacement of OH - by S 2-Substitution, presumably associated with the crystalline disordering induced by the rapid phase transformation at low temperature, this structural transition realizes the atomic-level uniform dispersion of Ni, Co, Mn multi-metal ions, and the multi-element random distribution characteristics and excellent phase homogeneity can effectively optimize the adsorption and desorption behavior of the reaction intermediates, thereby greatly enhancing the electrocatalytic activity of the catalyst in HER and SOR. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is the X-ray diffraction (XRD) diagram of the waste ternary lithium battery positive material powder obtained after disassembly in the experimental example; Figure 2 is the XRD diagram of the layered NiCoMn(OH) x / NF precursor and NiCoMnS x / NF catalyst synthesized in the experimental example; Figure 3 is the scanning electron microscope (SEM) diagram of the layered NiCoMn(OH) x / NF precursor synthesized in the experimental example; Figure 4 is the scanning electron microscope (SEM) diagram of the layered NiCoMn(OH) x / NF precursor synthesized in the experimental example; Figure 5 is the LSV curve of the HER of the NiCoMnS x / NF in the experimental example; Figure 6 is the LSV curve of the SOR of the NiCoMnS x / NF in the experimental example; Figure 7 is the LSV curve of the HER of the NiCoMnS x / NF-S in the experimental example; Figure 8 is the LSV curve of the SOR of the NiCoMnS x / NF-S in the experimental example. DETAILED DESCRIPTION

[0025] Embodiment 1 A method for preparing a ternary sulfide catalyst from waste batteries, comprising the following steps: S1, separation and collection of the positive material: the waste ternary lithium nickel cobalt manganese oxide battery is sequentially discharged, disassembled, and classified to obtain the positive material, and the waste ternary lithium nickel cobalt manganese oxide battery is LiNi 0.8 Co 0.1 Mn 0.1O2, the positive electrode material is cleaned by ultrasonic wave to strip the lithium nickel cobalt manganese oxide coating, the ultrasonic power is 200 W during the ultrasonic cleaning, and the ultrasonic cleaning time is 4 h; the stripped lithium nickel cobalt manganese oxide coating is centrifuged to obtain lithium nickel cobalt manganese oxide active powder, the centrifugation speed is 1000 rpm, and the centrifugation time is 4 min; S2, preparation of an electrodeposition leaching solution: the lithium nickel cobalt manganese oxide active powder obtained in S1 is added into a hydrochloric acid solution, the molar concentration of the hydrochloric acid solution is 3 mol / L, and the ratio of the lithium nickel cobalt manganese oxide active powder to the hydrochloric acid solution is 10 mmol: 20 mL; after stirring, a mixed solution is obtained, the stirring mode is magnetic stirring on a magnetic stirrer, and the stirring time is 20 h; the mixed solution is suction filtered to obtain a leaching solution containing metal ions; S3, preparation of a layered NiCoMn(OH) x / NF precursor: the leaching solution obtained in S2 is adjusted to a pH of 6, a NaOH solution with a molar concentration of 2 mol / L is used to adjust the pH of the leaching solution, the leaching solution is used as an electrolyte for primary electrodeposition, a blocky nickel foam is pretreated with a hydrochloric acid solution to obtain a / NF as a working electrode for primary electrodeposition, Ag / AgCl is taken as a reference electrode for primary electrodeposition, and Pt is taken as a counter electrode for primary electrodeposition; primary electrodeposition of metal ions is carried out at a constant voltage, the voltage for primary electrodeposition is -1 V (vs. Ag / AgCl), and the deposition time is 30 min; after the reaction is completed, the obtained solid substance is cooled, washed and dried; the solid substance is washed with distilled water and anhydrous ethanol for 3 times respectively, and then dried in a vacuum oven at 50 DEG C for 1.5 h, to obtain a layered NiCoMn(OH) x / NF precursor; The size of the blocky nickel foam is 1.5 cm x 1.5 cm, and the method for pretreating the blocky nickel foam with a hydrochloric acid solution is as follows: the blocky nickel foam is ultrasonically treated in a hydrochloric acid solution with a molar concentration of 4 mol / L for 25 min to remove oxides and impurities on the surface, and then washed with distilled water and anhydrous ethanol for 3 times respectively, and then dried in a vacuum oven at 50 DEG C for 1.5 h for standby use; S4, preparation of a NiCoMnS x / NF catalyst: a mixed solution of NaOH and Na2S is taken as an electrolyte for secondary electrodeposition, the molar concentration of NaOH in the electrolyte for secondary electrodeposition is 2 mol / L, the molar concentration of Na2S in the electrolyte for secondary electrodeposition is 2 mol / L, and the volume ratio of the electrolyte for primary electrodeposition to the electrolyte for secondary electrodeposition is 50:50; the layered NiCoMn(OH) xThe NiCoMnSx / NF ternary sulfide catalyst is obtained by the following steps: taking the NF precursor as a working electrode of secondary electrodeposition, taking Ag / AgCl as a reference electrode of secondary electrodeposition, and taking Pt as a counter electrode of secondary electrodeposition, and then performing secondary electrodeposition under a constant current, wherein the current of the secondary electrodeposition process is 0.5 A, and the deposition time is 50 min; after the reaction is completed, the obtained solid material is cooled, washed, and dried; when the solid material is cooled, washed, and dried, it is washed with distilled water and anhydrous ethanol respectively for 3 times, and then dried in a vacuum oven at 50 DEG C for 1.5 h, to obtain the NiCoMnSx / NF ternary sulfide catalyst.

[0026] Example 2 The difference between this example and Example 1 is that: The waste ternary lithium nickel-cobalt-manganese oxide battery is LiNi 0.33 Co 0.33 Mn 0.33 O2.

[0027] Example 3 The difference between this example and Example 1 is that: The waste ternary lithium nickel-cobalt-manganese oxide battery is LiNi 0.5 Co 0.2 Mn 0.3 O2.

[0028] Example 4 The difference between this example and Example 1 is that: The waste ternary lithium nickel-cobalt-manganese oxide battery is LiNi 0.6 Co 0.2 Mn 0.2 O2.

[0029] Example 5 The difference between this example and Example 1 is that: The waste ternary lithium nickel-cobalt-manganese oxide battery is LiNi 0.6 Co 0.2 Mn 0.2 O2 and LiNi 0.33 Co 0.33 Mn 0.33 O2.

[0030] Example 6 The difference between this example and Example 1 is that: The ultrasonic power is 180 W during the ultrasonic cleaning in S1, and the ultrasonic cleaning time is 3 h; the peeled lithium nickel-cobalt-manganese oxide coating is centrifuged to obtain a lithium nickel-cobalt-manganese oxide active powder, and the centrifugation speed is 800 rpm and the centrifugation time is 3 min.

[0031] Example 7 The difference between this example and Example 1 is that: The ultrasonic power in the ultrasonic cleaning in S1 is 240 W, and the ultrasonic cleaning time is 6 h. The peeled nickel cobalt manganese lithium coating is centrifuged to obtain nickel cobalt manganese lithium active powder. The centrifugal speed is 1200 rpm, and the centrifugal time is 6 min.

[0032] Example 8 The difference between this example and Example 1 is that: S2, preparation of the electrodeposition leaching solution: the nickel cobalt manganese lithium active powder obtained in S1 is added into a hydrochloric acid solution with a concentration of 1 mol / L. The ratio of the nickel cobalt manganese lithium active powder to the hydrochloric acid solution is 5 mmol: 20 mL. After stirring, a mixed solution is obtained. The stirring mode is magnetic stirring on a magnetic stirrer. The stirring time is 19 h. The mixed solution is suction filtered to obtain a leaching solution containing metal ions.

[0033] Example 9 The difference between this example and Example 1 is that: S2, preparation of the electrodeposition leaching solution: the nickel cobalt manganese lithium active powder obtained in S1 is added into a hydrochloric acid solution with a concentration of 6 mol / L. The ratio of the nickel cobalt manganese lithium active powder to the hydrochloric acid solution is 15 mmol: 20 mL. After stirring, a mixed solution is obtained. The stirring mode is magnetic stirring on a magnetic stirrer. The stirring time is 28 h. The mixed solution is suction filtered to obtain a leaching solution containing metal ions.

[0034] Example 10 The difference between this example and Example 1 is that: S3, preparation of the layered NiCoMn(OH) x / NF precursor: the leaching solution obtained in S2 is adjusted to a pH of 5 using a NaOH solution with a concentration of 1 mol / L as the electrolyte for the first electrodeposition. A blocky nickel foam is pretreated with a hydrochloric acid solution to obtain a working electrode for the first electrodeposition. Ag / AgCl is taken as the reference electrode for the first electrodeposition, and Pt is taken as the counter electrode for the first electrodeposition. The first electrodeposition of metal ions is carried out at a constant voltage of -1.5 V (vs. Ag / AgCl) for 10 min. After the reaction is completed, the obtained solid substance is cooled, washed and dried. The solid substance is washed with distilled water and anhydrous ethanol for 3 times respectively, and then dried in a vacuum oven at 45°C for 2 h for standby. A layered NiCoMn(OH) x / NF precursor is obtained.

[0035] Example 11 The difference between this example and Example 1 is that: S3. Preparation of layered NiCoMn(OH) by single electrodeposition x / NF precursor: The pH of the leaching solution obtained in S2 was adjusted to 7 using a 3 mol / L NaOH solution as the electrolyte for primary electrodeposition. Blocky nickel foam was pretreated with hydrochloric acid to obtain / NF, which served as the working electrode for primary electrodeposition. Ag / AgCl was used as the reference electrode, and Pt as the counter electrode. Primary electrodeposition of metal ions was performed under a constant voltage of -0.5V (vs. Ag / AgCl) for 60 min. After the reaction, the resulting solid was cooled, washed, and dried. The solid was washed three times each with distilled water and anhydrous ethanol, and then dried in a vacuum oven at 55℃ for 1 h to obtain layered NiCoMn(OH). x / NF precursor.

[0036] Example 12 The difference between this embodiment and Embodiment 1 is that: The size of the blocky nickel foam is 1cm×1cm. The method of pretreatment of the blocky nickel foam with hydrochloric acid solution is as follows: the blocky nickel foam is ultrasonically treated in a hydrochloric acid solution with a molar concentration of 3mol / L for 30min to remove surface oxides and impurities, then washed 3 times each with distilled water and anhydrous ethanol, and then dried in a vacuum oven at 55℃ for 1h for later use.

[0037] Example 13 The difference between this embodiment and Embodiment 1 is that: The size of the blocky nickel foam is 2cm×2cm. The method of pretreatment of the blocky nickel foam with hydrochloric acid solution is as follows: the blocky nickel foam is ultrasonically treated in a hydrochloric acid solution with a molar concentration of 5mol / L for 20min to remove surface oxides and impurities, then washed 3 times each with distilled water and anhydrous ethanol, and then dried in a vacuum oven at 45℃ for 2h before use.

[0038] Example 14 The difference between this embodiment and Embodiment 1 is that: S4, Secondary electrodeposition preparation of NiCoMnS x / NF catalyst: A mixed solution of NaOH and Na2S was used as the electrolyte for secondary electrodeposition. The molar concentration of NaOH and the molar concentration of Na2S in the secondary electrodeposition electrolyte were both 1 mol / L. The volume ratio of the primary electrodeposition electrolyte to the secondary electrodeposition electrolyte was 40:30. The layered NiCoMn(OH) obtained in S3 was then used. xThe / NF precursor was used as the working electrode for secondary electrodeposition, Ag / AgCl was used as the reference electrode for secondary electrodeposition, and Pt was used as the counter electrode for secondary electrodeposition. Secondary electrodeposition was carried out under a constant current of 0.05 A for 70 min. After the reaction was completed, the solid material was cooled, washed, and dried. The solid material was washed three times each with distilled water and anhydrous ethanol after cooling and drying. Then it was dried in a vacuum oven at 45 °C for 2 h to obtain the NiCoMnSx / NF ternary sulfide catalyst.

[0039] Example 15 The difference between this embodiment and Embodiment 1 is that: S4, Secondary electrodeposition preparation of NiCoMnS x / NF catalyst: A mixed solution of NaOH and Na2S was used as the electrolyte for secondary electrodeposition. The molar concentration of NaOH and Na2S in the secondary electrodeposition electrolyte was 3 mol / L, and the volume ratio of the primary electrodeposition electrolyte to the secondary electrodeposition electrolyte was 65:70. The layered NiCoMn(OH) obtained in S3 was then used. x The / NF precursor was used as the working electrode for secondary electrodeposition, Ag / AgCl was used as the reference electrode for secondary electrodeposition, and Pt was used as the counter electrode for secondary electrodeposition. Secondary electrodeposition was carried out under a constant current of 1.0 A for 10 min. After the reaction was completed, the solid material was cooled, washed, and dried. The solid material was washed three times each with distilled water and anhydrous ethanol after cooling and drying. Then it was dried in a vacuum oven at 55 °C for 1 h to obtain the NiCoMnSx / NF ternary sulfide catalyst.

[0040] Example 16 This embodiment provides an application of a ternary sulfide catalyst, which is prepared based on the method in Example 1, and is applied to the electrocatalytic hydrogen evolution reaction.

[0041] Example 17 This embodiment provides an application of a ternary sulfide catalyst, which is prepared based on the method in Example 1, and is applied to the sulfur ion oxidation reaction.

[0042] Experimental Example The NiCoMnSx / NF ternary sulfide catalyst prepared in Example 1 was used as an example for testing. The test results are as follows: Figures 1-5 As shown.

[0043] Figure 1The image shows the X-ray diffraction (XRD) pattern of the waste ternary lithium battery cathode material powder obtained after dismantling. All diffraction peaks are related to LiNi. 0.8 Co 0.1 Mn 0.1 The O2 corresponds well, proving that the cathode material obtained from the disassembly is lithium nickel cobalt manganese oxide.

[0044] Figure 2 The synthesized layered NiCoMn(OH) x / NF precursor and NiCoMnS x XRD pattern of / NF catalyst, NiCoMn(OH) x / NF diffraction peaks and NiCoMn(OH) x The Ni in the NF substrate corresponds well, indicating that the precursor has a typical layered hydroxide LDH structure; after electrodeposition and sulfidation, the peaks belonging to LDH disappear and no new peaks are generated, indicating that OH - During the vulcanization process, S 2- Substitution resulted in an amorphization effect in NiCoMnS. x The amorphous structure is likely due to disordered crystallization caused by a rapid phase transition during electrodeposition, which ensures the stability of Ni. 2+ Co 2+ Mn 2+ The uniform distribution.

[0045] Figure 3 The synthesized layered NiCoMn(OH) x Scanning electron microscope (SEM) images of the / NF precursor show a cluster-like morphology composed of nanospheres. Some nanospheres have wrinkles or layered textures on their surface, indicating that they are composed of stacked two-dimensional nanosheets.

[0046] Figure 4 The synthesized layered NiCoMn(OH) x Scanning electron microscope (SEM) image of the / NF precursor, inherited from NiCoMn(OH) x The morphology of spherical clusters assembled from the nanosheets of / NF.

[0047] Figure 5 and 6 They are NiCoMnS x The LSV curves of HER and SOR for / NF at 100 mA / cm² -2 At current density, NiCoMnS in the HER reaction x The overpotential of / NF is 0.153V, and the overpotential in the SOR reaction is 0.31V.

[0048] Figure 7 and Figure 8NiCoMnS prepared in x / NF-S is the synthesis condition and NiCoMnS x The conditions for electrodeposition ( / NF) are the same, except that a chemical reagent solution with the same concentrations of Mn, Co, and Ni as the electrodeposition leaching solution is used for electrodeposition; among other things... Figure 7 and 8 They are NiCoMnS x The LSV curves of HER and LSV curves of SOR in / NF-S at 100mAcm -2 At current density, NiCoMnS in the HER reaction x The overpotential of NF is 0.187V, and the overpotential in the SOR reaction is 0.32V.

[0049] NiCoMnS can be found x The performance of / NF-S is surprisingly slightly lower than that of NiCoMnS. x / NF, which may be due to the promoting effect of trace impurity elements in waste batteries, further illustrating the superiority of the resource-based preparation route of the present invention.

Claims

1. A method for preparing ternary sulfide catalysts using waste batteries, characterized in that, Includes the following steps: S1. Separation and collection of positive electrode materials: waste ternary nickel cobalt manganese lithium batteries are discharged, disassembled and classified in sequence to obtain positive electrode materials. The positive electrode materials are ultrasonically cleaned to remove the nickel cobalt manganese lithium oxide coating. The removed nickel cobalt manganese lithium oxide coating is centrifuged to obtain nickel cobalt manganese lithium oxide active powder. S2. Preparation of electrodeposition leachate: The lithium nickel cobalt manganese oxide active powder obtained in S1 is added to hydrochloric acid solution. The ratio of lithium nickel cobalt manganese oxide active powder to hydrochloric acid solution is 5~15 mmol: 20 mL. After stirring, a mixture is obtained. The mixture is filtered to obtain a leachate containing metal ions. S3. Preparation of layered NiCoMn(OH) by single electrodeposition x / NF precursor: The leaching solution obtained in S2 was adjusted to pH 5-7 and used as the electrolyte for primary electrodeposition. Bulk nickel foam was pretreated with hydrochloric acid solution to obtain / NF, which was used as the working electrode for primary electrodeposition. Ag / AgCl was used as the reference electrode for primary electrodeposition, and Pt was used as the counter electrode for primary electrodeposition. Primary electrodeposition of metal ions was performed under a constant voltage. After the reaction, the resulting solid material was cooled, washed, and dried to obtain layered NiCoMn(OH). x / NF precursor; S4, Secondary electrodeposition preparation of NiCoMnS x / NF catalyst: A mixed solution of NaOH and Na2S was used as the electrolyte for secondary electrodeposition, and the layered NiCoMn(OH) obtained in S3 was... x The / NF precursor was used as the working electrode for secondary electrodeposition, Ag / AgCl was used as the reference electrode for secondary electrodeposition, and Pt was used as the counter electrode for secondary electrodeposition. Secondary electrodeposition was carried out under a constant current. After the reaction was completed, the solid material was cooled, washed, and dried to obtain the NiCoMnSx / NF ternary sulfide catalyst.

2. The method for preparing a ternary sulfide catalyst using waste batteries according to claim 1, characterized in that, The spent ternary nickel-cobalt-manganese lithium batteries are LiNi 0.33 Co 0.33 Mn 0.33 O2, LiNi 0.5 Co 0.2 Mn 0.3 O2, LiNi 0.6 Co 0.2 Mn 0.2 O2, LiNi 0.8 Co 0.1 Mn 0.1 One or more of O2.

3. The method for preparing a ternary sulfide catalyst using waste batteries according to claim 1, characterized in that, In S1, the ultrasonic power during ultrasonic cleaning is 180~240W, the ultrasonic cleaning time is 3~6h, the centrifugal separation speed is 800~1200rpm, and the centrifugal separation time is 3~6min.

4. The method for preparing a ternary sulfide catalyst using waste batteries according to claim 1, characterized in that, In S2, the concentration of hydrochloric acid solution is 1~6 mol / L, and the stirring method is to place it on a magnetic stirrer for magnetic stirring for 19~28 hours.

5. The method for preparing a ternary sulfide catalyst using waste batteries according to claim 1, characterized in that, In S3, the pH of the leachate is adjusted using a NaOH solution with a molar concentration of 1~3 mol / L. The voltage for the first electrodeposition is -1.5~-0.5V (vs. Ag / AgCl), and the deposition time is 10~60 min. The solid material is washed three times each with distilled water and anhydrous ethanol, and then dried in a vacuum oven at 45~55℃ for 1~2 h before use.

6. The method for preparing a ternary sulfide catalyst using waste batteries according to claim 1, characterized in that, In S3, the size of the blocky nickel foam is 1~2cm×1~2cm. The method for pretreating the blocky nickel foam with hydrochloric acid solution is as follows: the blocky nickel foam is ultrasonically treated in a hydrochloric acid solution with a molar concentration of 3~5mol / L for 20~30min to remove surface oxides and impurities, then washed 3 times each with distilled water and anhydrous ethanol, and then dried in a vacuum oven at 45~55℃ for 1~2h for later use.

7. The method for preparing a ternary sulfide catalyst using waste batteries according to claim 1, characterized in that, In S4, the concentration of NaOH in the electrolyte for secondary electrodeposition is 1-3 mol / L, the concentration of Na2S is 1-3 mol / L, the volume ratio of the electrolyte for primary electrodeposition to the electrolyte for secondary electrodeposition is 40-65:30-70, the current for secondary electrodeposition is 0.05-1.0 A, the deposition time is 10-70 min, and after the solid material is cooled, it is washed three times each with distilled water and anhydrous ethanol, and then dried in a vacuum oven at 45-55℃ for 1-2 h before use.

8. The application of a ternary sulfide catalyst, said catalyst being prepared based on the method according to any one of claims 1 to 7, characterized in that, The catalyst is used in electrocatalytic hydrogen evolution reaction and sulfur ion oxidation reaction.

Images