Preparation method for recycling and regenerating Mo / F co-doped manganese-sodium-rich electric ternary positive electrode material from waste nickel cobalt lithium manganate positive electrode

Abstract

The invention discloses a preparation method for recycling and regenerating a Mo / F co-doped manganese-sodium-rich electric ternary positive electrode material from a waste nickel cobalt lithium manganate positive electrode, and relates to a method for synthesizing and regenerating a Mo / F co-doped layered nickel cobalt manganese oxide manganese-rich (Na < 0.67 > Ni < 0.21 > Co < 0.1 > Mn < 0.67 > Mo < x > F < y > O < 2 >) ternary positive electrode material by recycling and reusing a waste power battery and application of the Mo / F co-doped manganese-sodium-rich electric ternary positive electrode material. The method comprises the following steps: leaching a waste ternary positive electrode material by a wet method, co-precipitating, calcining and regenerating to prepare the Mo / F co-doped sodium ion layered transition metal oxide positive electrode material (Na < 0.67 > Ni < 0.21 > Co < 0.1 > Mn < 0.67 > Mo < x > F < y > O < 2 >). An electrochemical test result shows that the positive electrode has excellent normal-temperature performance, and meanwhile, the problem of slow dynamics of the positive electrode at low temperature is broken through. According to the invention, the waste power battery positive electrode is recycled, and is regenerated and converted into the sodium ion battery positive electrode material with abundant raw materials through a modification strategy. A spinel surface layer is formed by introducing Mo / F, and the cycle performance of the layered transition metal oxide positive electrode material of the regenerated sodium-ion battery is improved through the synergistic effect of Mo / F. The preparation process is simple, high in operability, wide in raw material source, low in cost and suitable for large-scale production, and meets environmental requirements.

Description

Technical Field

[0001] This invention belongs to the field of waste battery recycling technology, specifically relating to a method for recycling and regenerating Mo / F co-doped sodium-ion battery cathode materials from waste ternary lithium-ion battery cathode materials. Background Technology

[0002] Rechargeable lithium-ion batteries have become an important means of electrochemical energy storage. Their long cycle life and high energy density make them widely used in various portable electronic devices and new energy vehicles. The rapid development of new energy vehicles has greatly boosted the production of lithium-ion batteries. Recycling used batteries can alleviate the lithium resource shortage and create both economic and environmental benefits.

[0003] However, the problem of lithium resource scarcity remains severe. Sodium, an element in the same group as lithium, is abundant, and its working principle is similar to that of lithium-ion batteries, offering a feasible solution to the lithium resource shortage. Among them, P2-type layered metal oxides (Na₂) x P2 phase cathode materials (P2-phase Cathodes) have attracted much attention due to their excellent cycle stability and rate performance. However, they unfortunately suffer from severe phase transitions, stress accumulation, and transition metal dissolution during charge and discharge, which seriously restricts their practical applications. Studies have shown that doping with low-valence cations such as magnesium (Mg), lithium (Li), copper (Cu), and nickel (Ni) can effectively alleviate these problems. However, when layered materials are exposed to air, nickel / sodium mixing is easily triggered. This cation mixing leads to harmful structural distortions and forms residual alkali on the material surface, significantly increasing sodium ion diffusion resistance. Existing low-valence cation doping has limited effectiveness in suppressing cation migration; therefore, there is an urgent need to develop a novel control strategy that can simultaneously suppress irreversible phase transitions, the Jahn-Teller effect, and cation migration.

[0004] Therefore, this invention prepares a regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide manganese-rich ternary cathode material by recycling waste ternary cathodes. A spinel interface is constructed by introducing the high-valence cation molybdenum (Mo) and the anion fluoride (F), which significantly suppresses the Jan Taylor effect. This interface generates a barrier effect on the particle surface. This barrier effectively inhibits the contact between particles and moisture and gases, thereby significantly reducing cation mixing. With the improvement of electron conduction and sodium ion transport rates, the rate performance of the material is significantly improved. Summary of the Invention

[0005] This invention prepares a regenerated Mo / F co-doped manganese-rich sodium cathode material with a P2 phase spinel surface by acid leaching, co-precipitation, and high-temperature calcination of pretreated waste nickel-cobalt-manganese oxide cathode powder. The purpose of this invention is to provide a method for recycling and regenerating Mo / F co-doped nickel-cobalt-manganese oxide-rich manganese-sodium cathode material from waste ternary lithium-ion batteries. Simultaneously, addressing the problems of harmful phase transitions, transition metal dissolution, and slow low-temperature kinetics inherent in layered sodium cathode materials, this invention adjusts the transition metal ratio and introduces high-valence metal cations and anions to synergistically eliminate TM layer slippage and Na+. + With orderly vacancy spaces and a simple recycling process, the resource utilization of used ternary lithium batteries has been realized.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] Step 1: Acid Immersion

[0008] A certain mass of waste lithium nickel cobalt manganese oxide cathode powder that has been disassembled, separated and removed of binders is placed in a sulfuric acid solution of a certain concentration. A certain amount of hydrogen peroxide is added for mixing, heating and stirring to leach out the metal ions. Manganese sulfate, nickel sulfate and cobalt sulfate are added to adjust the proportion of metal ions in the metal ion leachate to obtain a metal ion leachate.

[0009] Step 2: Co-precipitation

[0010] N2 is bubbled into the metal ion leaching solution to prevent the oxidation of manganese ions. A certain concentration of ammonia and Na2CO3 solution are simultaneously pumped into the metal ion leaching solution, while adjusting the pH and maintaining a certain temperature and time. After stirring at this temperature for a certain period, a certain amount of (NH4)6Mo7O is added. 24 A mixed solution prepared with NaF was pumped into the mixture at a certain rate and stirred for a certain period of time; the precipitate was filtered and washed with pure water, and the precipitate was vacuum dried to obtain a nickel cobalt manganese carbonate precursor containing Mo and F ions;

[0011] Step 3: Calcination

[0012] (1) The nickel cobalt manganese carbonate precursor containing Mo and F ions dried in step two is mixed with Na2CO3 in a certain proportion, and anhydrous ethanol is added for dispersion ball milling to obtain a uniformly dispersed slurry.

[0013] (2) The slurry obtained in step (1) is placed in a vacuum drying oven and dried thoroughly to obtain a uniformly mixed powder;

[0014] (3) The uniformly mixed powder obtained in step (2) is calcined in a muffle furnace at a heating rate of 5℃ / min. -1First, the temperature is raised to 500℃ and held for 5 hours, then raised to 850-900℃ and held for 12 hours to obtain regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide rich in manganese (Na). 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo x F y O2) Ternary cathode material;

[0015] Step 4: Application of Sodium-ion Battery Cathode Materials

[0016] The regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide sodium-rich cathode material obtained in step three is used as the active component of the sodium-ion battery cathode. It is mixed with conductive carbon black and binder PVDF in a mass ratio of 8:1:1, ground evenly, and then coated onto aluminum foil as the cathode. The sodium metal sheet is used as the anode. The cells are assembled into button cells in a glove box with water and oxygen <0.1ppm using 1.0M NaClO4 / EC / DMC / FEC as the electrolyte. Alternatively, hard carbon is mixed with conductive carbon black and sodium carboxymethyl cellulose in a mass ratio of 90:5:5, ground evenly, and then coated onto copper foil as the anode. The cathode is then matched with the cathode prepared above and assembled into a full cell.

[0017] The ternary lithium-ion battery cathode material, lithium nickel cobalt manganese oxide, mentioned in step one above, is recycled from waste lithium-ion power battery ternary materials from Xiamen Tungsten New Energy, including LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 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; the manganese sulfate used to adjust the metal ion ratio is selected from anhydrous manganese sulfate or manganese sulfate monohydrate, the nickel sulfate is selected from anhydrous nickel sulfate, nickel sulfate hexahydrate or nickel sulfate heptahydrate, and the cobalt sulfate is selected from anhydrous cobalt sulfate or cobalt sulfate tetrahydrate. The amount of hydrogen peroxide added in the leachate is 0.5-5 vol%, and the sulfuric acid concentration is 0.5-2 M; the solid-liquid ratio of waste nickel cobalt manganese oxide lithium cathode powder to metal ion leachate is 10-60 g / L, the stirring temperature is controlled at 60-80℃, and the leaching time is 1-2 h.

[0018] In step two above, the ammonia concentration is 0.1–1.5 M, and the Na₂CO₃ solution concentration is 0.2–2.0 M. The ammonia and Na₂CO₃ solutions of the above concentrations are pumped into the metal ion leaching solution from step one using a peristaltic pump at a controlled rate. The pH of the metal ion leaching solution is controlled at 8.0 ± 0.1. The solution is heated and stirred at 60–80 °C for 8–12 hours. After heating and stirring for a certain period, a certain amount of (NH₄)₆Mo₇O₇ is added. 24 The mixture of NaF and NaF was pumped into the mixture at a certain rate and stirred for 0.5 to 4 hours.

[0019] In step three above, the ratio of the total amount of nickel, cobalt, and manganese elements in the nickel-cobalt-manganese carbonate precursor containing Mo and F ions to the amount of sodium carbonate, i.e., n (Ni+Co+Mn) :n (Na2CO3) =1:0.335.

[0020] The waste nickel-cobalt-manganese lithium oxide cathode material prepared by the above-described preparation method of this invention is a layered transition metal oxide Na. The resulting Mo / F co-doped manganese-rich sodium ternary cathode material is a layered transition metal oxide. 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo x F y O2; where 0 < x < 0.02, 0 < y < 0.02, and x + y = 0.02.

[0021] The present invention relates to the application of the recycled Mo / F co-doped sodium-rich manganese ternary cathode material obtained by the above-described preparation method of the present invention, or the above-described recycled Mo / F co-doped sodium-rich manganese ternary cathode material in button cells or assembled into full cells.

[0022] Compared with existing technologies, this invention has the following advantages:

[0023] 1. The recycling and reuse method of waste ternary lithium-ion battery cathode material in this invention is simple, which can not only realize the resource utilization of waste ternary power batteries, but also realize large-scale application.

[0024] 2. This recycling method applies waste ternary battery materials to sodium-ion batteries while simultaneously creating a sodium-ion battery cathode material with both excellent, mild, and low-temperature performance.

[0025] 3. This method addresses the challenges of harmful phase transitions, transition metal dissolution, and slow low-temperature kinetics in regenerated layered P2-phase sodium cathode materials. It constructs a spinel interface by introducing high-valence molybdenum ions and fluorine ions, which significantly suppress the Jan Taylor effect. This interface creates a barrier effect on the particle surface. This barrier effectively inhibits contact between particles and moisture and gases, thereby significantly reducing cation mixing. The Mo / F synergistic effect effectively suppresses harmful phase transitions while simultaneously inhibiting the dissolution of transition metal ions. Attached Figure Description

[0026] Figure 1 This is the high-performance regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide sodium-rich cathode material (Na) obtained in Example 1. 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 XRD pattern of O2).

[0027] Figure 2 This is the high-performance regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide sodium-rich cathode material (Na) obtained in Example 1. 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 Scanning electron microscope (SEM) and transmission electron microscope (TEM) images of O2.

[0028] Figure 3-a , 3-b This is the high-performance regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide sodium-rich cathode material (Na) obtained in Example 1. 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 Cycling performance of O2 as a cathode material in sodium-ion batteries at room temperature (0.5C) and at -40°C (0.2C).

[0029] Figure 4-a , 4-b This is the high-performance regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide sodium-rich cathode material (Na) obtained in Example 1. 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 Rate performance of O2 as a cathode material in sodium-ion batteries at room temperature and -40°C.

[0030] Figure 5-a , 5-b The high-performance regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide sodium-rich cathode (Na) obtained in Example 1 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 Cycling performance of a full cell assembled with O2 and a hard carbon anode at 0.5C. Detailed Implementation

[0031] The following examples illustrate the recycling of waste nickel-cobalt-manganese lithium oxide cathode powder from waste lithium-ion power battery ternary materials, including LiNi, from Xiamen Tungsten New Energy. 1 / 3 Co 1 / 3 Mn 1 / 3 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.

[0032] Example 1

[0033] 1) Take 0.5g of lithium nickel cobalt manganese oxide (LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 0.5 g of O2, 0.5 g of MnSO4·H2O, and 1.7 g of NiSO4·6H2O were placed in 50 mL of 0.5 M sulfuric acid solution, 2 vol% H2O2 was added, and the mixture was kept at 80 °C and stirred for 2 h to obtain a metal ion leaching solution.

[0034] 2) N2 was bubbled into the above metal ion leaching solution. 10 mL of 0.2 M ammonia solution and 10 mL of 0.8 M Na2CO3 solution were simultaneously pumped into the metal ion leaching solution. The pH was adjusted to 8.0 ± 0.1, and the solution was stirred at 60 °C for 9 h to obtain a precipitate mixture. 0.029 g of (NH4)6Mo7O was weighed. 24 (Commercially available chemical reagent, Aladdin Company) and 0.007 g NaF were dissolved in 10 mL of deionized water to prepare a mixed solution, which was then pumped into the above precipitate mixture and stirred for 3 h. The precipitate was filtered and washed with pure water, and the precipitate was vacuum dried to obtain a nickel-cobalt-manganese carbonate precursor containing Mo and F ions.

[0035] 3) The nickel-cobalt-manganese carbonate precursor containing Mo and F ions obtained after vacuum drying is mixed with sodium carbonate. The ratio of the total amount of nickel, cobalt, and manganese elements in the nickel-cobalt-manganese carbonate precursor to the amount of sodium carbonate is n. (Ni+Co+Mn) :n (Na2CO3) =1:0.335, add anhydrous ethanol as a dispersant and ball mill for 1 hour, then vacuum dry the uniformly dispersed mixture for later use.

[0036] 4) Place the uniformly dispersed mixture obtained in step 3) in a muffle furnace and heat at 5°C for 5 min. -1 The temperature was increased to 500℃ and calcined for 5 hours, then increased at 5℃ for 5 minutes. -1 The temperature was increased to 850℃ and calcined for 12 h to obtain regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide rich in manganese (Na). 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 O2) Ternary cathode material.

[0037] The regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide (Na₂O₃) prepared in this embodiment is rich in manganese (Na₂O₃). 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 O2) Ternary cathode material, used as the active component of the sodium-ion battery cathode, is mixed with conductive agent carbon black and binder PVDF in a mass ratio of 8:1:1, ground uniformly, and then coated onto aluminum foil as the working electrode (i.e., the cathode). A sodium metal sheet serves as the anode, and a 1.0M NaClO4 / EC / DMC / FEC electrolyte is used to assemble a button-type 2025 battery. Hard carbon, conductive agent carbon black, and sodium carboxymethyl cellulose are mixed with carbon black and ground uniformly in a mass ratio of 90:5:5, then coated onto copper foil as the anode, and combined with the cathode prepared above to assemble a full battery.

[0038] Figure 1 It can be seen that the P2 phase regenerated positive electrode Na was obtained. 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 O2. (From) Figure 2 It can be seen that Na 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 O2 has good crystallinity, is generally spherical, and has formed a spinel structure on its surface. Figure 3-a , 3-b As can be seen, Na 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 O2 maintained a specific capacity of 117 mAh g after 100 cycles at a current density of 0.5C. -1 Even after 100 cycles at -40°C, the capacity retention remained at 96%. Figure 4-a As can be seen, Na 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 The O2 cathode exhibits superior rate performance at room temperature. Figure 4-b The data shows that even at -40℃, Na 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 O2 still exhibits superior rate performance. Figure 5-a , 5-b This indicates that Na 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 O2 cathodes have practical application potential.

[0039] Example 2

[0040] 1) Take 0.5g of lithium nickel cobalt manganese oxide (LiNi 0.5 Co 0.2 Mn 0.3 1.13 g of MnSO4·H2O and 0.045 g of CoSO4·4H2O were placed in 50 mL of 0.5 M sulfuric acid solution, 2 vol% H2O2 was added, and the mixture was stirred at 80 °C for 2 h to obtain a metal ion leaching solution.

[0041] 2) N2 was bubbled into the above metal ion leaching solution. 10 mL of 0.2 M ammonia solution and 10 mL of 0.8 M Na2CO3 solution were simultaneously pumped into the metal ion leaching solution. The pH was adjusted to 8.0 ± 0.1, and the solution was stirred at 60 °C for 9 h to obtain a precipitate mixture. 0.0205 g of (NH4)6Mo7O was weighed. 24(Commercially available chemical reagent, Aladdin Company) and 0.005 g NaF were dissolved in 10 mL of deionized water to prepare a mixed solution, which was then pumped into the above precipitate mixture and stirred for 3 h. The precipitate was filtered and washed with pure water, and the precipitate was vacuum dried to obtain a nickel-cobalt-manganese carbonate precursor containing Mo and F ions.

[0042] 3) The nickel-cobalt-manganese carbonate precursor containing Mo and F ions obtained after vacuum drying is mixed with sodium carbonate. The ratio of the total amount of nickel, cobalt, and manganese elements in the nickel-cobalt-manganese carbonate precursor to the amount of sodium carbonate is n. (Ni+Co+Mn) :n (Na2CO3) =1:0.335, add anhydrous ethanol as a dispersant and ball mill for 1 hour, then vacuum dry the uniformly dispersed mixture for later use.

[0043] 4) Place the mixture obtained in step 3) in a muffle furnace and heat at 5°C for 5 min. -1 The temperature was increased to 500℃ and calcined for 5 hours, then increased at 5℃ for 5 minutes. -1 The temperature was increased to 850℃ and calcined for 12 h to obtain regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide rich in manganese (Na). 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 O2) Ternary cathode material.

[0044] The regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide (Na₂O₃) prepared in this embodiment is rich in manganese (Na₂O₃). 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 O2) Ternary cathode material, used as the active component of the sodium-ion battery cathode, is mixed with conductive agent carbon black and binder PVDF in a mass ratio of 8:1:1, ground uniformly, and then coated onto aluminum foil as the working electrode (i.e., the cathode). A sodium metal sheet serves as the anode, and a 1.0M NaClO4 / EC / DMC / FEC electrolyte is used to assemble a button-type 2025 battery. Hard carbon, conductive agent carbon black, and sodium carboxymethyl cellulose are mixed with carbon black and ground uniformly in a mass ratio of 90:5:5, then coated onto copper foil as the anode, and combined with the cathode prepared above to assemble a full battery.

[0045] Example 3

[0046] 1) Take 0.5g of lithium nickel cobalt manganese oxide (LiNi 0.6 Co 0.2 Mn 0.21.49 g of MnSO4·H2O and 0.1 g of CoSO4·4H2O were placed in 50 mL of 0.5 M sulfuric acid solution, 2 vol% H2O2 was added, and the mixture was stirred at 80 °C for 2 h to obtain a metal ion leaching solution.

[0047] 2) N2 was bubbled into the above metal ion leaching solution. 10 mL of 0.2 M ammonia solution and 10 mL of 0.8 M Na2CO3 solution were simultaneously pumped into the metal ion leaching solution. The pH was adjusted to 8.0 ± 0.1, and the solution was stirred at 60 °C for 9 h to obtain a precipitate mixture. 0.025 g of (NH4)6Mo7O was weighed. 24 (Commercially available chemical reagent, Aladdin Company) and 0.006 g NaF were dissolved in 10 mL of deionized water to prepare a mixed solution, which was then pumped into the above precipitate mixture and stirred for 3 h. The precipitate was filtered and washed with pure water, and the precipitate was vacuum dried to obtain a nickel-cobalt-manganese carbonate precursor containing Mo and F ions.

[0048] 3) The nickel-cobalt-manganese carbonate precursor containing Mo and F ions obtained after vacuum drying is mixed with sodium carbonate. The ratio of the total amount of nickel, cobalt, and manganese elements in the nickel-cobalt-manganese carbonate precursor to the amount of sodium carbonate is n. (Ni+Co+Mn) :n (Na2CO3) =1:0.335, add anhydrous ethanol as a dispersant and ball mill for 1 hour, then vacuum dry the uniformly dispersed mixture for later use.

[0049] 4) Place the mixture obtained in step 3) in a muffle furnace and heat at 5°C for 5 min. -1 The temperature was increased to 500℃ and calcined for 5 hours, then increased at 5℃ for 5 minutes. -1 The temperature was increased to 850℃ and calcined for 12 hours to obtain regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide rich in sodium manganese (Na). 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 O2) positive electrode material.

[0050] The regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide (Na₂O₃) prepared in this embodiment is rich in manganese (Na₂O₃). 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01O2) Ternary cathode material, used as the active component of the sodium-ion battery cathode, is mixed with conductive agent carbon black and binder PVDF in a mass ratio of 8:1:1, ground uniformly, and then coated onto aluminum foil as the working electrode (i.e., the cathode). A sodium metal sheet serves as the anode, and a 1.0M NaClO4 / EC / DMC / FEC electrolyte is used to assemble a button-type 2025 battery. Hard carbon, conductive agent carbon black, and sodium carboxymethyl cellulose are mixed with carbon black and ground uniformly in a mass ratio of 90:5:5, then coated onto copper foil as the anode, and combined with the cathode prepared above to assemble a full battery.

[0051] Example 4

[0052] 1) Take 50g of lithium nickel cobalt manganese oxide (LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 44.67 g of MnSO4 and 100 g of NiSO4·6H2O were placed in 2.5 L of 2 M sulfuric acid solution, 5 vol% H2O2 was added, and the mixture was kept at 80 °C and stirred for 2 h to obtain a metal ion leaching solution.

[0053] 2) N2 was bubbled into the above metal ion leaching solution. 300 mL of 0.5 M ammonia solution and 300 mL of 1.5 M Na2CO3 solution were simultaneously pumped into the metal ion leaching solution. The pH was adjusted to 8.0 ± 0.1, and the solution was stirred at 60 °C for 8 hours to obtain a precipitate mixture. 2.9 g of (NH4)6Mo7O was weighed. 24 (Commercially available chemical reagent, Aladdin Company) and 0.7 g NaF were dissolved in 500 mL of deionized water to prepare a mixed solution, which was then pumped into the above precipitate mixture and stirred for 4 h. The precipitate was filtered and washed with pure water, and the precipitate was vacuum dried to obtain a nickel-cobalt-manganese carbonate precursor containing Mo and F ions.

[0054] 3) The nickel-cobalt-manganese carbonate precursor containing Mo and F ions obtained after vacuum drying is mixed with sodium carbonate. The ratio of the total amount of nickel, cobalt, and manganese elements in the nickel-cobalt-manganese carbonate precursor to the amount of sodium carbonate is n. (Ni+Co+Mn) :n (Na2CO3) =1:0.335, add anhydrous ethanol as a dispersant and ball mill for 1 hour, then vacuum dry the uniformly dispersed mixture for later use.

[0055] 4) Place the mixture obtained in step 3) in a muffle furnace and heat at 5°C for 5 min. -1 The temperature was increased to 500℃ and calcined for 5 hours, then increased at 5℃ for 5 minutes. -1 The temperature was increased to 850℃ and calcined for 12 h to obtain regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide rich in manganese (Na). 0.67 Ni 0.21 Co 0.1 Mn0.67 Mo 0.01 F 0.01 O2) Ternary cathode material.

[0056] The regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide (Na₂O₃) prepared in this embodiment is rich in manganese (Na₂O₃). 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 O2) Ternary cathode material, used as the active component of the sodium-ion battery cathode, is mixed with conductive agent carbon black and binder PVDF in a mass ratio of 7:2:1, ground uniformly, and then coated onto aluminum foil as the working electrode (i.e., the cathode). A sodium metal sheet serves as the anode, and a 1.0M NaClO4 / EC / DMC / FEC electrolyte is used to assemble a button-type 2025 battery. Hard carbon, conductive agent carbon black, and sodium carboxymethyl cellulose are mixed with carbon black and ground uniformly in a mass ratio of 90:5:5, then coated onto copper foil as the anode, and combined with the cathode prepared above to assemble a full battery.

[0057] Example 5

[0058] 1) Take 5 kg of lithium nickel cobalt manganese oxide (LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 4.47 kg of MnSO4 and 110 kg of NiSO4 were placed in 100 L of 2 M sulfuric acid solution, 5 vol% H2O2 was added, and the mixture was kept at 80 °C and stirred for 2 h to obtain a metal ion leaching solution.

[0059] 2) N2 was introduced into the above metal ion leaching solution. 10 L of 0.5 M ammonia solution and 10 L of 1.5 M Na2CO3 solution were simultaneously pumped into the metal ion leaching solution. The pH was adjusted to 8.0 ± 0.1, and the solution was stirred at 60 °C for 12 h to obtain a precipitate mixture. 290 g of (NH4)6Mo7O was weighed. 24 (Commercially available chemical reagent, Aladdin Company) and 70g NaF were dissolved in 20L of deionized water to prepare a mixed solution, which was then pumped into the above precipitate mixture and stirred for 4 hours. The precipitate was filtered and washed with pure water, and the precipitate was vacuum dried to obtain a nickel-cobalt-manganese carbonate precursor containing Mo and F ions.

[0060] 3) The nickel-cobalt-manganese carbonate precursor containing Mo and F ions obtained after vacuum drying is mixed with sodium carbonate. The ratio of the total amount of nickel, cobalt, and manganese elements in the nickel-cobalt-manganese carbonate precursor to the amount of sodium carbonate is n. (Ni+Co+Mn) :n (Na2CO3) =1:0.335, add anhydrous ethanol as a dispersant and ball mill for 1 hour, then vacuum dry the uniformly dispersed mixture for later use.

[0061] 4) Place the mixture obtained in step 3) in a muffle furnace and heat at 5°C for 5 min. -1 The temperature was increased to 500℃ and calcined for 5 hours, then increased at 5℃ for 5 minutes. -1 The temperature was increased to 900℃ and calcined for 12 hours to obtain a manganese-rich (Na) Mo / F co-doped layered nickel-cobalt-manganese oxide. 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 O2) Ternary cathode material.

[0062] The regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide (Na₂O₃) prepared in this embodiment is rich in manganese (Na₂O₃). 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo 0.01 F 0.01 O2) Ternary cathode material, used as the active component of the sodium-ion battery cathode, is mixed with conductive agent carbon black and binder PVDF in a mass ratio of 7:2:1, ground uniformly, and then coated onto aluminum foil as the working electrode (i.e., the cathode). A sodium metal sheet serves as the anode, and a 1.0M NaClO4 / EC / DMC / FEC electrolyte is used to assemble a button-type 2025 battery. Hard carbon, conductive agent carbon black, and sodium carboxymethyl cellulose are mixed with carbon black and ground uniformly in a mass ratio of 90:5:5, then coated onto copper foil as the anode, and combined with the cathode prepared above to assemble a full battery.

Claims

1. A method for preparing a Mo / F co-doped manganese-rich sodium ternary cathode material from recycled waste lithium nickel cobalt manganese oxide cathodes, comprising the following steps: Step 1: Acid Immersion A certain mass of waste lithium nickel cobalt manganese oxide cathode powder is placed in a sulfuric acid solution of a certain concentration, and a certain amount of hydrogen peroxide is added for mixing, heating, stirring and leaching. Manganese sulfate, nickel sulfate and cobalt sulfate are added to adjust the proportion of metal ions in the metal ion leaching solution to obtain a metal ion leaching solution. Step 2: Co-precipitation; N2 is bubbled into the metal ion leaching solution to prevent the oxidation of manganese ions. A certain concentration of ammonia and Na2CO3 solution are simultaneously pumped into the metal ion leaching solution, while adjusting the pH and maintaining a certain temperature and time. After stirring at this temperature for a certain period, a certain amount of (NH4)6Mo7O is added. 24 A mixed solution prepared with NaF was pumped into the mixture at a certain rate and stirred for a certain period of time; the precipitate was filtered and washed with pure water, and the precipitate was vacuum dried to obtain a nickel cobalt manganese carbonate precursor containing Mo and F ions; Step 3: Calcination (1) The nickel cobalt manganese carbonate precursor containing Mo and F ions dried in step two is mixed with Na2CO3 in a certain proportion, and anhydrous ethanol is added for dispersion ball milling to obtain a uniformly dispersed slurry. (2) The slurry obtained in step (1) is placed in a vacuum drying oven and dried thoroughly to obtain a uniformly mixed powder; (3) The uniformly mixed powder obtained in step (2) is calcined in a muffle furnace at a heating rate of 5°C. o C min -1 First, heat to 500 o Keep warm at C for 5 hours, then raise the temperature to 850~900. o After holding at C for 12 h, a regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide sodium-rich cathode material was obtained. Step 4: Application of Sodium-ion Battery Cathode Materials The regenerated Mo / F co-doped layered nickel-cobalt-manganese oxide sodium-rich positive electrode material obtained in step three is used as the active component of the positive electrode of a sodium-ion battery. It is mixed with conductive carbon black and binder PVDF in a mass ratio of 8:1:1, ground evenly, and then coated onto aluminum foil as the positive electrode. A metallic sodium sheet is used as the negative electrode. The battery is assembled into a button cell in a glove box with water and oxygen <0.1 ppm using 1.0 M NaClO4 / EC / DMC / FEC as the electrolyte. Alternatively, hard carbon is mixed with conductive carbon black and sodium carboxymethyl cellulose in a mass ratio of 90:5:5, ground evenly, and then coated onto copper foil as the negative electrode. The negative electrode is then matched with the positive electrode prepared above and assembled into a full cell.

2. The preparation method according to claim 1, characterized in that... In step one, the waste nickel-cobalt-manganese lithium cathode powder is recycled from the waste lithium-ion power battery ternary materials of Xiamen Tungsten New Energy, including LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 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; the manganese sulfate used to adjust the metal ion ratio is selected from anhydrous manganese sulfate or manganese sulfate monohydrate, the nickel sulfate is selected from anhydrous nickel sulfate, nickel sulfate hexahydrate or nickel sulfate heptahydrate, and the cobalt sulfate is selected from anhydrous cobalt sulfate or cobalt sulfate tetrahydrate; the amount of hydrogen peroxide added in the metal ion leaching solution is 0.5~5 vol%, and the sulfuric acid concentration is 0.5~2 M; the solid-liquid ratio of the waste lithium nickel cobalt manganese oxide cathode powder to the metal ion leaching solution is 10~60 g / L. -1 The stirring temperature should be controlled at 60~80°C. o C, leaching time 1~2 h.

3. The preparation method according to claim 1, characterized in that... In step two, the ammonia concentration is 0.1~1.5 M, and the Na2CO3 solution concentration is 0.2~2.0 M. The ammonia and Na2CO3 solutions of these concentrations are pumped into the metal ion leaching solution from step one using a peristaltic pump at a controlled rate. The pH of the metal ion leaching solution is controlled at 8.0±0.1, and the temperature is maintained at 60~80°C. o Heat and stir at temperature C for 8-12 hours, then add a certain amount of (NH4)6Mo7O after a certain heating and stirring time. 24 A mixed solution of NaF and NaF was pumped into the mixture at a certain rate and stirred for 0.5 to 4 hours.

4. The preparation method according to claim 1, characterized in that... In step three, the ratio of the total amount of nickel, cobalt, and manganese elements in the nickel-cobalt-manganese carbonate precursor containing Mo and F ions to the amount of sodium carbonate, i.e., n (Ni+Co+Mn) : n (Na2CO3) =1:0.

335.

5. The waste nickel-cobalt-manganese lithium oxide cathode material recycled and regenerated by the preparation method according to any one of claims 1-4 is a layered transition metal oxide Na. 0.67 Ni 0.21 Co 0.1 Mn 0.67 Mo x F y O2; where 0 <x<0.02, 0<y<0.02, x+y=0.

02.

6. The application of the recycled Mo / F co-doped sodium-rich manganese ternary cathode material obtained by the preparation method according to any one of claims 1-4, or the recycled Mo / F co-doped sodium-rich manganese ternary cathode material according to claim 5, in button cells or assembled into full cells.

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