Method for preparing medium-entropy ordered alloy M3NiCoMn (at) Ti1-y (NiCoMn) yO2-x catalyst based on waste ternary lithium battery positive electrode valuable metal recovery
By recovering valuable metals from spent ternary lithium batteries and preparing an oxygen-vacancy type Ti1-y(NiCoMn)yO2-x support, and loading an entropy-ordered alloy catalyst of M3NiCoMn@Ti1-y(NiCoMn)yO2-x, the high cost of traditional metallurgical methods and the problem of lithium-oxygen battery catalyst synthesis are solved, achieving efficient transition metal recovery and performance improvement of lithium-oxygen batteries.
Patent Information
- Application Number
- CN202511751367.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-26
- Publication Date
- 2026-02-24
AI Technical Summary
Traditional metallurgical methods for recovering transition metals from lithium-ion batteries are costly and energy-intensive. The synthesis of positive electrode catalysts for lithium-oxygen batteries suffers from problems such as alloy particle agglomeration and unstable catalytic performance. The disposal of waste lithium-ion batteries causes environmental pollution.
Valuable metals were recovered from the cathode of spent ternary lithium batteries, and oxygen-vacancy type Ti1-y(NiCoMn)yO2-x support was prepared by Joule thermal shock method. M3NiCoMn@Ti1-y(NiCoMn)yO2-x entropy-ordered alloy catalyst was loaded on it and synthesized using noble metal Pt solution to achieve interfacial interaction between metal and oxide and form stable catalytic active sites.
This technology enables low-cost and high-efficiency transition metal recovery, improves the catalytic performance and structural stability of lithium-oxygen batteries, reduces environmental pollution, lowers energy consumption, and enhances the activity and selectivity of catalysts.
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Figure CN121551022A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of recycling technology for spent ternary lithium batteries, specifically relating to the preparation of a medium-entropy ordered alloy M3NiCoMn@Ti based on the recovery of valuable metals from the cathode of spent ternary lithium batteries. 1-y (NiCoMn) y O 2-x Catalyst methods. Background Technology
[0002] 1. Limitations of traditional metallurgical methods for recovering transition metals from lithium-ion batteries: While lithium-ion batteries are now widely used, improper disposal of used batteries can lead to heavy metal and water pollution, wasting the metal raw materials they contain. Therefore, the recycling of transition metals from lithium-ion batteries is of great significance. However, traditional metallurgical methods rely on high-temperature smelting processes, which result in high costs due to high smelting temperatures and large fuel consumption. Furthermore, the smelting process generates harmful byproducts, creating secondary environmental pressure.
[0003] 2. The scarcity of transition metal resources is becoming increasingly prominent: Lithium-ion battery production is highly dependent on scarce metal resources such as lithium, cobalt, nickel, and manganese, and the contradiction between supply and demand of resources and the risk of price fluctuations are difficult to alleviate.
[0004] 3. Although lithium-oxygen batteries can overcome some of the defects of lithium-ion batteries, they still have technical bottlenecks: Lithium-oxygen batteries boast a theoretical energy density of up to 3500 Wh / kg, far exceeding the theoretical energy density limit of 1000 Wh / kg for traditional lithium-ion batteries. The positive electrode reactant in lithium-oxygen batteries is oxygen, and the addition of a highly efficient catalyst significantly reduces polarization during charge and discharge, enhancing reaction stability and effectively mitigating the potential risks of deflagration and similar problems caused by temperature runaway during the charge and discharge processes of lithium-ion batteries. However, the research on positive electrode catalysts for lithium-oxygen batteries faces the following bottlenecks: while alloy particles are commonly used as catalysts, their synthesis presents certain challenges, primarily in controlling the size and dispersion of metal alloy particles on the carrier surface. During high-temperature alloying, alloy particles are prone to agglomeration or intermetallic sintering due to prolonged high surface energy, leading to increased particle size, reduced exposure of active sites, and potential electrode blockage. Summary of the Invention
[0005] This invention discloses a method for preparing a medium-entropy ordered alloy M3NiCoMn@Ti based on the recycling of valuable metals from the cathode of spent ternary lithium batteries. 1-y (NiCoMn) y O 2-x The purpose of the catalyst method is to solve the problems described in 1-3 of the prior art.
[0006] To achieve the above objectives, the technical solution of the present invention is as follows: Medium-entropy ordered alloy M3NiCoMn@Ti was prepared based on the recycling of valuable metals from the cathode of spent ternary lithium batteries. 1-y (NiCoMn) y O 2-x The catalyst method includes the following steps: Step 1: Recover valuable metal NiCoMn ion solution from the positive electrode of waste ternary lithium batteries; Step 2: Synthesis of oxygen-vacancy type Ti via Joule thermal shock 1-y (NiCoMn) y O 2-x Carrier powder; Step 3: Add NiCoMn ion solution and Ti 1-y (NiCoMn) y O 2-x The carrier powder and Pt-based noble metal solution were added to a 1:1 mixture of deionized water and anhydrous ethanol in a certain proportion, and stirred in an oil bath until completely evaporated to obtain the precursor. Step 4: Subject the precursor to a second Joule thermal shock to obtain the target product M3NiCoMn@Ti 1-y (NiCoMn) y O 2-x catalyst.
[0007] Preferably, step 1 includes: after fully discharging the waste ternary lithium battery, peeling off its positive electrode sheet, cutting the peeled positive electrode sheet into small pieces, placing it in a 50mL centrifuge tube, adding 20mL of N-methylpyrrolidone (NMP) and 20mL of dimethyl carbonate (DMC) mixture, sonicating for 5-8 hours to remove the positive electrode material, making the mixture a turbid liquid, removing the remaining positive electrode sheet, centrifuging and drying to obtain black powder containing Li, Ni, Co, and Mn precipitates; taking 0.5g of black powder and dissolving it in 40mL of deionized water, adding sodium hydroxide to adjust the pH of the solution to be greater than 10, heating and stirring at 70℃ for 3-5 hours, centrifuging to collect the precipitate, drying to obtain NiCoMn-containing powder A; taking 0.5g of powder A and dissolving it in diluted dilute sulfuric acid, stirring at room temperature for 3 hours, centrifuging to collect the supernatant, letting it stand for 24 hours, and then taking the upper impurity-removed liquid, which is the recovered NiCoMn ion solution.
[0008] Preferably, step 2 includes: dissolving 100 mg of metatitanic acid powder and 0.02 mL of NiCoMn ion solution together in anhydrous ethanol, evaporating the solution by stirring in an oil bath at 85°C until dry, subjecting the resulting powder to Joule thermal shock, heating it to 900°C within 5 seconds and holding it for 5-10 seconds, and then allowing it to cool naturally to room temperature to obtain oxygen-vacancy type Ti. 1-y (NiCoMn) y O 2-xCarrier powder.
[0009] Preferably, step 3 includes: adding 50 mg of oxygen-vacancy type Ti 1-y (NiCoMn) y O 2-x The carrier powder was dissolved in a mixed solvent of 20 mL deionized water and 20 mL anhydrous ethanol. Then, according to the stoichiometric ratio of the number of moles of noble metal to the total number of moles of transition metal of 3:1, Pt-based noble metal solution and NiCoMn ion solution were added respectively. The mixture was heated and stirred in an oil bath at 85 °C until the solution was evaporated to dryness, and the powder obtained was the precursor of the target product.
[0010] Preferably, step 4 includes: subjecting the precursor to Joule thermal shock, heating it to 1200°C within 5-10 seconds under a nitrogen atmosphere, holding it at that temperature for 5-10 seconds, and then cooling it to room temperature within 5-10 seconds, resulting in a black powder, which is M3NiCoMn@Ti. 1-y (NiCoMn) y O 2-x catalyst.
[0011] This invention is based on the recovery of valuable metals from the cathode of spent ternary lithium batteries to prepare a medium-entropy ordered alloy M3NiCoMn@Ti. 1-y (NiCoMn) y O 2-x The beneficial effects of the catalytic method are: (1) Advantages of the process for recovering valuable transition metals from the cathode of spent ternary lithium batteries: The electrolyte of spent ternary lithium batteries contains toxic substances such as fluorine-containing organic compounds. If not centrally treated, it will cause serious pollution to water and soil resources. If heavy metal elements such as Ni, Co, and Mn in the cathode enter the environment, they will accumulate through the food chain, causing long-term ecological risks and ultimately endangering human health. Currently, the Ni, Co, and Mn required for experiments and industries mainly come from metal smelting, which involves certain energy consumption and carbon emissions. This scheme uses a low-cost, low-energy chemical extraction method to recover valuable metals from spent ternary lithium batteries, forming a closed-loop production and recycling system of "source material-product-waste-recycled raw materials". This is not only a good solution to alleviate heavy metal pollution from spent batteries, but also improves the utilization rate of metal resources. The chemical reagents used in the recycling process of this scheme are inexpensive and the process is highly stable, with great industrialization potential.
[0012] (2) Preparation of oxygen-vacancy type Ti by Joule thermal shock 1-y (NiCoMn) y O 2-xAdvantages of the carrier process: This method employs Joule thermal shock. A small amount of NiCoMn ion solution and Ti source are dissolved together, stirred, and evaporated to dryness. Excess H and O elements in the metatitanic acid are then released by Joule thermal shock, leaving the chemically stable TiO2 at high temperatures. Simultaneously, NiCoMn ions are reduced at high temperatures, providing sufficient chemical reaction energy for them to coordinate with O and substitute for Ti sites in TiO2. Random atoms from Ni, Co, and Mn occupy Ti sites in TiO2 during the synthesis process. Due to the different outer electron structures and electronegativity of NiCoMn and Ti, electrons near the occupied sites are transferred to establish charge balance. This characteristic allows NiCoMn to successfully induce the generation of surrounding oxygen vacancies through the occupation of Ti sites, thus preparing oxygen-vacancy-type Ti. 1-y (NiCoMn) y O 2-x Support. The increased oxygen vacancy density provides more selectable sites for the subsequent addition of Pt-based noble metal M, resulting in a richer array of active sites on the catalyst surface for the ORR / OER catalytic process and improved catalytic efficiency.
[0013] (3) Advantages of constructing alloy particles using a second Joule thermal shock: Metal alloy particles on the support are prone to aggregation due to prolonged high surface energy, continuously growing and covering active sites, thus reducing catalytic efficiency. This method uses Joule thermal shock to instantly raise the temperature to over 1000℃ within a heating time of as little as 5 seconds. The extreme holding time provides sufficient energy for metal reduction and alloying, followed by rapid cooling to room temperature. This instantaneous heating and rapid cooling thermal shock method facilitates the small and uniform distribution of M3NiCoMn ordered alloy particles on Ti. 1-y (NiCoMn) y O 2-x On the carrier, it promotes the orderly arrangement of metal atoms in the alloy particles and improves catalytic efficiency.
[0014] (4) Advantages of medium-entropy ordered alloys: The medium-entropy ordered alloy M3NiCoMn prepared by this scheme achieves a balance between entropy characteristics and compositional complexity and practical performance, overcoming the problems of low-entropy alloys with poor catalytic performance due to their single composition and high-entropy alloys with unstable catalytic performance and high synthesis cost due to their complex composition. At the atomic scale, transition metal atoms are inserted between adjacent noble metal atoms. This arrangement forms a tight and strong atomic framework. The active metal atoms are confined within the atomic framework composed of other metal atoms. The highly ordered structure greatly increases the activation energy required to break the atomic framework of the metal particles, ensuring the structural stability of the material as a catalyst throughout the catalytic process. Due to differences in electronegativity and the different valence electron configurations between the metals, alloying adjusts the overall electron configuration, generating more selective catalytic sites and optimizing the electron density of active sites. This achieves "diversification" and "quality improvement" of catalytic active sites in the ORR / OER process, thereby improving the reaction efficiency of ORR and OER. Precise electronic control provides reaction intermediates with more selectable active sites and faster reaction rates, regulating the direction of the reaction. Under this effect, more charge-discharge reaction intermediates are naturally transformed along the correct reaction pathway, thus avoiding the generation of byproducts.
[0015] (5) Catalytic advantages of metal-support interaction: M3NiCoMn and Ti 1-y (NiCoMn) y O 2-x Support-support interaction (MSI) enhances catalytic activity and selectivity during the reaction process. This is achieved by NiCoMn occupying Ti sites, thus enhancing Ti's catalytic activity and selectivity. 1-y (NiCoMn) y O 2-x The support is rich in oxygen vacancies. After the addition of the Pt-based noble metal M in the subsequent alloying step, electron transfer and lattice distortion occur at the metal-oxide interface, forming special "interfacial active sites." Because the generation of oxygen vacancies causes a local increase in electron density, and M atoms have empty electron orbitals in their outer shells, electrons flow from the high electron density of the oxygen vacancies to the outermost empty orbitals of M, changing the filling state of the Pt outer orbitals and altering the energy level of its d orbitals. This causes a shift in the d-band center, regulating the catalytic selectivity and adsorption / desorption intensity of oxygen-containing intermediates during the reaction, improving the adsorption / desorption configuration of the intermediates, guiding the formation of the target product in the ORR / OER process, enhancing the reaction kinetics, and reducing side reactions. This is because M3NiCoMn reacts with Ti... 1-y (NiCoMn) y O 2-xElectronic reconstruction at the support interface enables the metal alloy particles to grow firmly on the support through the electronic bonding of MO, preventing the metal alloy particles from falling off or moving and adsorbing on the support surface, thus preventing metal sintering and ensuring the stability of the catalyst structure.
[0016] (6) Universality and cost advantage of the synthesis approach: In the M3NiCoMn structure mentioned in this scheme, M can be other Pt-based noble metals, such as Ru, Ir, etc., which are multi-component mixtures and are applicable to the preparation of alloys of various metals. The source materials are inexpensive, the cost is low, the synthesis process is simple, and it is suitable for industrial production. Attached Figure Description
[0017] Figure 1 It is an ordered medium-entropy alloy M3NiCoMn@Ti 1-y (NiCoMn) y O 2-x Transmission electron microscope image; Figure 2 It is an ordered medium-entropy alloy M3NiCoMn@Ti 1-y (NiCoMn) y O 2-x X-ray powder diffraction curve; Figure 3 It is an ordered medium-entropy alloy M3NiCoMn@Ti 1-y (NiCoMn) y O 2-x Deep charge-discharge performance curves for lithium-oxygen batteries; Figure 4 It is an ordered medium-entropy alloy M3NiCoMn@Ti 1-y (NiCoMn) y O 2-x CV performance curves for use in lithium-oxygen batteries; Figure 5 It is an ordered medium-entropy alloy M3NiCoMn@Ti 1-y (NiCoMn) y O 2-x Rate performance time-voltage curves for lithium-oxygen batteries. Detailed Implementation
[0018] The following description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
[0019] The following embodiments can be understood as illustrating a part of the structure or method of the present invention individually, or as combining the embodiments to explain the broader structure or method of the present invention.
[0020] Example 1: Medium-entropy ordered alloy M3NiCoMn@Ti was prepared based on the recycling of valuable metals from the cathode of spent ternary lithium batteries. 1-y (NiCoMn) y O 2-x The catalyst method includes the following steps: Step 1: Recover valuable metal NiCoMn ion solution from the positive electrode of waste ternary lithium batteries; Step 2: Synthesis of oxygen-vacancy type Ti via Joule thermal shock 1-y (NiCoMn) y O 2-x Carrier powder; Step 3: Add NiCoMn ion solution and Ti 1-y (NiCoMn) y O 2-x The carrier powder and Pt-based noble metal solution were added to a 1:1 mixture of deionized water and anhydrous ethanol in a certain proportion, and stirred in an oil bath until completely evaporated to obtain the precursor. Step 4: Subject the precursor to a second Joule thermal shock to obtain the target product M3NiCoMn@Ti 1-y (NiCoMn) y O 2-x catalyst.
[0021] Example 2: Based on Example 1, step 1 includes: after fully discharging the waste ternary lithium battery, peeling off its positive electrode sheet, cutting the peeled positive electrode sheet into 5cm*1cm pieces, placing them in a 50mL centrifuge tube, adding 20mL of N-methylpyrrolidone (NMP) and 20mL of dimethyl carbonate (DMC) mixture, sonicating for 5-8 hours to remove the positive electrode material, making the mixture a turbid liquid, removing the remaining positive electrode sheet, centrifuging and drying to obtain black powder containing Li, Ni, Co, and Mn precipitates; taking 0.5g of black powder and dissolving it in 40mL of deionized water, adding sodium hydroxide to adjust the pH of the solution to be greater than 10, heating and stirring at 70℃ for 3-5 hours, centrifuging to collect the precipitate, drying to obtain NiCoMn-containing powder A; taking 0.5g of powder A and dissolving it in diluted dilute sulfuric acid, stirring at room temperature for 3 hours, centrifuging to collect the supernatant, letting it stand for 24 hours, and then taking the upper impurity-removed liquid, which is the recovered NiCoMn ion solution.
[0022] Example 3: Based on Examples 1 and 2, step 2 includes: dissolving 100 mg of metatitanic acid powder and 0.02 mL of NiCoMn ion solution together in anhydrous ethanol, stirring and evaporating to dryness in an oil bath at 85°C, subjecting the resulting powder to Joule thermal shock, heating to 900°C within 5 seconds and holding for 5-10 seconds, and then naturally cooling to room temperature to obtain oxygen-vacancy type Ti. 1-y (NiCoMn) y O 2-x Carrier powder.
[0023] Example 4: Based on Examples 1-3, step 3 includes: adding 50 mg of oxygen-vacancy type Ti 1-y (NiCoMn) y O 2-x The carrier powder was dissolved in a mixed solvent of 20 mL deionized water and 20 mL anhydrous ethanol. Then, according to the stoichiometric ratio of the number of moles of noble metal to the total number of moles of transition metal of 3:1, Pt-based noble metal solution and NiCoMn ion solution were added respectively. The mixture was heated and stirred in an oil bath at 85 °C until the solution was evaporated to dryness, and the powder obtained was the precursor of the target product.
[0024] Example 5: Based on Examples 1-4, step 4 includes: subjecting the precursor to Joule thermal shock, heating it to 1200°C within 5-10 seconds under a nitrogen atmosphere, holding it at that temperature for 5-10 seconds, and then cooling it to room temperature within 5-10 seconds. The resulting black powder is M3NiCoMn@Ti. 1-y (NiCoMn) y O 2-x .
[0025] Working principle of the invention: refer to Figure 1-5 As shown, this invention recovers valuable transition metals Ni, Co, and Mn from spent ternary lithium batteries. Metatitanic acid powder and a NiCoMn ion solution are co-dissolved and evaporated to dryness, followed by Joule thermal shock method to prepare oxygen-vacancy type Ti with Ni, Co, and Mn occupying Ti sites. 1-y (NiCoMn) y O 2-x As a carrier, it was then prepared on Ti by a second Joule thermal shock. 1-y (NiCoMn) y O 2-x Catalyst M3NiCoMn@Ti for the top-loaded ordered medium-entropy alloy M3NiCoMn 1-y (NiCoMn) y O 2-x(Where M is a Pt-based noble metal, such as Pt, Ru, Ir, or a mixture of multiple components thereof). In this scheme, metatitanic acid powder is used as the Ti source, NiCoMn ion solution recovered from the cathode of waste ternary lithium batteries is used as the transition metal source, and Pt-based noble metal solution is used as the noble metal source. Metatitanic acid powder and a small amount of NiCoMn ion solution are dissolved in anhydrous ethanol, heated and stirred until dry to obtain powder. The powder is then subjected to Joule thermal shock under N2 atmosphere to release excess H and O elements, with the aim of leaving TiO2, which is chemically stable at high temperatures. During this process, NiCoMn atoms reduced at high temperatures occupy Ti sites in TiO2, causing surrounding electron rearrangement and creating oxygen vacancies. The final black powder obtained is oxygen-vacancy type Ti. 1-y (NiCoMn) y O 2-x The aforementioned black powder, Pt-based noble metal solution, and NiCoMn ion solution were added to a mixture of deionized water and anhydrous ethanol. A medium-entropy ordered alloy of M3NiCoMn was constructed by a second Joule thermal shock, thus synthesizing M3NiCoMn@Ti. 1-y (NiCoMn) y O 2-x Catalysts. Catalysts prepared by this method can significantly improve the performance of lithium-oxygen batteries when applied to them.
[0026] In the specific scheme, a transition metal ion solution rich in valuable NiCoMn is recovered from waste ternary lithium batteries using methods such as discharge, ultrasound, alkaline washing, acid washing, oil bath, and centrifugation. M3NiCoMn@Ti is then prepared via a two-stage Joule thermal shock method. 1-y (NiCoMn) y O 2-x Catalyst. NiCoMn ion solution and metatitanic acid powder were dissolved in anhydrous ethanol, stirred, evaporated to dryness, and subjected to Joule thermal shock to obtain oxygen-vacancy type Ti. 1-y (NiCoMn) y O 2-x As a carrier. Ti 1-y (NiCoMn) y O 2-x Powdered NiCoMn ion solution and Pt-based noble metal solution were added to a 1:1 mixture of anhydrous ethanol and deionized water in a specific ratio. The mixture was heated and stirred in an oil bath until it evaporated to dryness to obtain precursor powder. The precursor powder was then subjected to a second Joule thermal shock at 1200℃ for 5-10 seconds under a N2 atmosphere, followed by natural cooling to room temperature. The valuable metals M, Ni, Co, and Mn were reduced under the instantaneous high temperature and formed an alloy to obtain oxygen-vacancy type Ti. 1-y (NiCoMn) y O 2-xThe catalyst supported on ordered medium-entropy alloy M3NiCoMn particles is the final target product of this scheme. During the first Joule thermal shock to prepare the support, a small amount of NiCoMn ions are added and occupy Ti sites in TiO2. Due to the differences in the outer electron structures of transition metals Ni, Co, and Mn with Ti atoms, electrons around these sites rearrange, resulting in effective electron compensation and the creation of oxygen vacancies around the transition metal sites, providing growth sites for subsequent alloy particles. Traditional tube furnace annealing for alloy particle preparation suffers from the problem of endless particle growth during heating due to its long heating time. The high-temperature instantaneous impact of the second Joule thermal shock not only avoids excessive particle growth but also provides sufficient energy for alloying of the metal components, achieving the formation of an ordered M3NiCoMn alloy structure, thus preparing a highly efficient catalyst for lithium-oxygen batteries.
[0027] In summary, this invention provides a method for recovering valuable metals from the cathode of spent ternary lithium batteries, supplementing them with Pt-based noble metals to prepare a medium-entropy ordered alloy M3NiCoMn, and then loading it onto an oxygen-vacancy type Ti. 1-y (NiCoMn) y O 2-x The catalyst preparation method described above, when applied to the cathode catalysis of lithium-oxygen batteries to improve electrochemical performance, has the following advantages: 1. This method utilizes discharge, ultrasonication, alkaline washing, acid washing, oil bath, and centrifugation to recover valuable transition metals Ni, Co, and Mn solutions from the cathodes of spent ternary lithium batteries. This effectively alleviates the pollution caused by spent batteries entering the environment and addresses the low resource reuse rate inherent in the disposal of spent batteries. The reagents used in the recycling process are all commonly used chemical reagents in modern industrial production, with low cost and high industrialization potential: sodium hydroxide can be prepared in large quantities by electrolyzing saturated brine and is widely used in industrial production processes requiring an alkaline environment; the core raw materials for sulfuric acid preparation are industrial byproducts such as sulfur and pyrite, which are inexpensive and commonly prepared using the contact method, resulting in a stable and cost-effective process. This recycling process has practical value in aligning with actual production and industrial applications.
[0028] 2. By adding a small amount of NiCoMn ion solution during the support synthesis process, Ni, Co, and Mn occupy Ti sites, thus preparing oxygen-vacancy type Ti. 1-y (NiCoMn) y O 2-x As a support for catalyst synthesis, this novel approach involves minimal metal doping during material synthesis. Joule thermal shock provides sufficient reaction energy for NiCoMn to occupy Ti sites, thereby creating oxygen vacancies by altering the electronic structure. Oxygen-vacancy Ti 1-y (NiCoMn) y O 2-xThis provides ample growth sites for the subsequent addition of the Pt-based noble metal M to form an ordered alloy structure. In this way, the M3NiCoMn alloy particles in this scheme exhibit growth sites within the oxygen-vacancy-type Ti... 1-y (NiCoMn) y O 2-x By loading a high-efficiency catalyst, more effective active catalytic surface area is exposed, effectively improving catalytic efficiency.
[0029] 3. Instantaneous heating using Joule thermal shock avoids the alloy growth and sintering caused by conventional prolonged annealing. This method employs Joule thermal shock to raise the reaction temperature to 1200℃ within 5 seconds and hold it for 5-10 seconds, followed by rapid cooling to room temperature. This fully reduces the four valuable metals (Pt, Ni, Co, and Mn) in the solution, alloying them into a stable, ordered structure. It also adjusts the electron configuration and coordination environment between the metals, resulting in small, uniform alloy particles loaded onto Ti. 1-y (NiCoMn) y O 2-x This creates a highly advantageous load-bearing method.
[0030] 4. Noble metals and transition metals form a medium-entropy ordered alloy structure in M3NiCoMn. In the M atomic sequence, transition metal atoms are inserted between adjacent M atoms, stabilizing the catalyst structure and overcoming the problem of insufficient catalytic activity associated with single metal components. The ordered metal atomic framework anchors different atoms to each other, giving the nano-alloy particles a more stable structure. The ordered arrangement of different metal atoms provides M3NiCoMn medium-entropy ordered alloy particles with a unique coordination environment and electronic structure, enriching the catalytic sites of reaction intermediates and enhancing catalytic activity and selectivity.
[0031] 5. This method has a novel synthesis concept and simple operation. The required raw materials are widely used in existing industrial production and have low cost, which makes this method have good industrialization potential. As a positive electrode catalyst, it can effectively improve the electrochemical performance of lithium-oxygen batteries and provide new possibilities for the practical application of lithium-oxygen batteries.
Claims
1. Preparation of medium-entropy ordered alloy M3NiCoMn@Ti based on the recycling of valuable metals from spent ternary lithium battery cathodes 1-y (NiCoMn) y O 2-x The catalytic method is characterized by, Includes the following steps: Step 1: Recover valuable metal NiCoMn ion solution from the positive electrode of waste ternary lithium batteries; Step 2: Synthesis of oxygen-vacancy type Ti via Joule thermal shock 1-y (NiCoMn) y O 2-x Carrier powder; Step 3: Add NiCoMn ion solution and Ti 1-y (NiCoMn) y O 2-x The carrier powder and Pt-based noble metal solution were added to a 1:1 mixture of deionized water and anhydrous ethanol in a certain proportion, and stirred in an oil bath until completely evaporated to obtain the precursor. Step 4: Subject the precursor to a second Joule thermal shock to obtain the target product M3NiCoMn@Ti 1-y (NiCoMn) y O 2-x catalyst.
2. The method for preparing entropy-ordered alloy M3NiCoMn@Ti based on the recycling of valuable metals from spent ternary lithium battery cathodes as described in claim 1. 1-y (NiCoMn) y O 2-x The catalytic method is characterized by, Step 1 includes: after fully discharging the waste ternary lithium battery, peeling off its positive electrode sheet, cutting the peeled positive electrode sheet into small pieces, placing it in a 50mL centrifuge tube, adding 20mL of N-methylpyrrolidone and 20mL of dimethyl carbonate mixture, sonicating for 5-8 hours to remove the positive electrode material, making the mixture a turbid liquid, removing the remaining positive electrode sheet, centrifuging and drying to obtain black powder containing Li, Ni, Co, and Mn precipitates; taking 0.5g of black powder and dissolving it in 40mL of deionized water, adding sodium hydroxide to adjust the pH of the solution to be greater than 10, heating and stirring at 70℃ for 3-5 hours, centrifuging to collect the precipitate, drying to obtain NiCoMn-containing powder A; taking 0.5g of powder A and dissolving it in diluted dilute sulfuric acid, stirring at room temperature for 3 hours, centrifuging to collect the supernatant, letting it stand for 24 hours, and then taking the upper impurity-removed liquid, which is the recovered NiCoMn ion solution.
3. The method for preparing entropy-ordered alloy M3NiCoMn@Ti based on the recycling of valuable metals from spent ternary lithium battery cathodes as described in claim 2. 1-y (NiCoMn) y O 2-x The catalytic method is characterized by, Step 2 includes: dissolving 100 mg of metatitanic acid powder and 0.02 mL of NiCoMn ion solution together in anhydrous ethanol, stirring and evaporating to dryness in an oil bath at 85 °C, subjecting the resulting powder to Joule thermal shock, heating to 900 °C within 5 seconds and holding for 5-10 seconds, and then naturally cooling to room temperature to obtain oxygen-vacancy type Ti. 1-y (NiCoMn) y O 2-x Carrier powder.
4. The method for preparing entropy-ordered alloy M3NiCoMn@Ti based on the recycling of valuable metals from spent ternary lithium battery cathodes as described in claim 3. 1-y (NiCoMn) y O 2-x The catalytic method is characterized by, Step 3 includes: adding 50 mg of oxygen-vacancy type Ti 1-y (NiCoMn) y O 2-x The carrier powder was dissolved in a mixed solvent of 20 mL deionized water and 20 mL anhydrous ethanol. Then, according to the stoichiometric ratio of the number of moles of noble metal to the total number of moles of transition metal of 3:1, Pt-based noble metal solution and NiCoMn ion solution were added respectively. The mixture was heated and stirred in an oil bath at 85 °C until the solution was evaporated to dryness, and the powder obtained was the precursor of the target product.
5. The method for preparing entropy-ordered alloy M3NiCoMn@Ti based on the recycling of valuable metals from spent ternary lithium battery cathodes as described in claim 4. 1-y (NiCoMn) y O 2-x The catalytic method is characterized by, Step 4 includes: subjecting the precursor to Joule thermal shock, heating it to 1200℃ in a nitrogen atmosphere for 5-10 seconds, holding it at that temperature for 5-10 seconds, and then cooling it to room temperature for 5-10 seconds. The resulting black powder is M3NiCoMn@Ti. 1-y (NiCoMn) y O 2-x catalyst.