A short-process resource recycling method for waste lithium-ion battery ternary positive electrode materials

Abstract

The present invention discloses a short-process resource recycling method for waste lithium-ion battery ternary positive electrode materials, belonging to the field of waste battery resource recycling. The technical scheme of the present invention is as follows: using recycled waste lithium-ion battery ternary positive electrode materials as raw materials, the raw materials are subjected to chemical oxidation treatment and chemical sulfurization treatment, and the sulfurized ternary composite oxide materials are added with appropriate functional additives to prepare alkaline secondary battery positive electrodes and assemble into alkaline secondary batteries. The present invention can efficiently recycle waste lithium-ion battery ternary positive electrode materials and use them for alkaline secondary battery positive electrodes, thereby realizing short-process recycling and regeneration of waste ternary positive electrode materials.

Description

Technical Field

[0001] The invention belongs to the technical field of resource recycling of waste lithium-ion battery positive electrode materials, and specifically relates to a short-process resource recycling method for waste lithium-ion battery ternary positive electrode materials. Background Art

[0002] Lithium-ion batteries are widely used in portable electronic devices, pure electric vehicles, hybrid electric vehicles and other electronic devices due to their high energy density, long cycle life and no memory effect. However, with the mass production and widespread use of lithium-ion batteries, the amount of waste lithium-ion batteries has also increased. If these waste batteries are not handled in a timely and reasonable manner, a large amount of environmental pollution and resource waste will be caused. The environmental pollution problem and the reasonable resource recycling and utilization of waste lithium-ion power batteries have become a common concern and urgent problem to be solved at home and abroad at present and in the future. The solution to this problem is not only conducive to environmental protection, but also conducive to the recycling of resources, and has great practical significance. Among all types of lithium-ion batteries, ternary lithium-ion batteries have a large market share in the field of electric vehicles due to their high energy density, which will be accompanied by the generation of a large number of waste ternary lithium-ion batteries. Under the dual requirements of resource recycling and environmentally friendly production, the research on the resource recycling of waste ternary lithium-ion batteries is of great significance. Solving the resource waste and environmental pollution problems caused by waste ternary lithium-ion batteries has become a hot issue worldwide.

[0003] According to current literature reports, since nickel and cobalt resources have a high recycling value, the main method for recycling waste ternary lithium-ion batteries is hydrometallurgy. The hydrometallurgical process uses mechanical methods to break the metal shell of the battery, and then adopts leaching, precipitation, ion exchange, adsorption and other methods to obtain metal compounds. The metal recovered is of high purity, but it requires a large amount of acid, alkali and organic reagents, the reaction process is long and not environmentally friendly. In order to solve the above problems, directly preparing new battery positive electrode materials from waste lithium-ion battery positive electrode materials through simple treatment has become a new research idea. This route has the advantages of being green, efficient, short process and low cost. It will greatly shorten the technical process and cycle of lithium-ion battery recycling, save costs, and increase recycling value. It has become the key to the development of waste ternary positive electrode material recycling technology. The repair and regeneration method of repairing positive electrode materials by simply supplementing lithium or metal elements has attracted the attention of researchers. However, it is difficult to completely repair the electrochemical activity of waste ternary positive electrode materials for the following reasons: the recycled waste lithium-ion battery ternary positive electrode materials have different conditions during use (including the number of cycles and whether they are overcharged or overused), which will cause great differences in the properties of the recycled materials (including particle size, processing performance and specific surface area, etc.). Therefore, the development of a short-process recycling and reuse technology for waste lithium-ion battery ternary positive electrode materials is particularly important for the sustainable development of my country's new energy industry, which can not only save resources and reduce costs, but also protect the environment. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a short-process resource recycling method for waste lithium-ion battery ternary positive electrode materials. The method has a simple process and a short process, realizes the recycling and reuse of waste lithium-ion battery ternary positive electrode materials, effectively reduces resource consumption and reduces battery production costs.

[0005] The present invention adopts the following technical scheme to solve the above technical problems, a short-process resource recycling method for waste lithium-ion battery ternary positive electrode materials, characterized in that the specific process is: the recycled waste lithium-ion battery ternary positive electrode materials are subjected to chemical oxidation treatment in an alkaline solution dissolved with a persulfate oxidant to obtain a ternary composite oxide material, and then the ternary composite oxide material is used as an alkaline secondary battery positive electrode active material to prepare an alkaline secondary battery positive electrode plate and used to assemble an alkaline secondary battery; the waste lithium-ion battery ternary positive electrode material is LiNi x Co y Mn z O2 or LiNi x Co y Al z One or more of O2, LiNi x Co y Mn zIn O2, x+y+z=1, x>0.3, y>0, z>0, LiNi x Co y Al z In O2, x+y+z=1, x>0.5, y>0, z>0, and the corresponding ternary composite oxide material is Ni x Co y Mn z O2 or Ni x Co y Al z One or more of O2, Ni x Co y Mn z In O2, x+y+z=1, x>0.3, y>0, z>0, Ni x Co y Al z In O2, x+y+z=1, x>0.5, y>0, z>0, and the persulfate oxidant is one or more of ammonium persulfate, potassium persulfate or sodium persulfate.

[0006] It is further defined that the ternary positive electrode material of the waste lithium-ion battery is 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 or LiNi 0.8 Co 0.15 Al 0.05 O2 one or more; the corresponding ternary composite oxide material is Ni 0.5 Co 0.2 Mn 0.3 O2, Ni 0.6 Co 0.2 Mn 0.2 O2,Ni 0.8 Co 0.1 Mn 0.1 O2 or Ni 0.8 Co 0.15 Al 0.05 One or more of O2.

[0007] It is further defined that the ternary composite oxide material is chemically sulfurized in a sulfur source salt solution to obtain a sulfurized ternary composite oxide material, and the sulfurized ternary composite oxide material is then used as an alkaline secondary battery positive electrode active material to prepare an alkaline secondary battery positive electrode plate and to assemble an alkaline secondary battery, and the sulfur source salt is one or more of sodium sulfide, thiourea or thiopropionamide.

[0008] It is further defined that when preparing the positive electrode plate of the alkaline secondary battery, a functional additive is added to the positive electrode active material of the alkaline secondary battery, and the functional additive is nickel molybdate, nickel tungstate, nickel oxyhydroxide, chromium oxide, chromium hydroxide, strontium oxide, strontium hydroxide, layered hydroxide [Co x M y N Z (OH)2]·[(B a- ) b ·mH2O], layered oxyhydroxide Co x M y N Z OOH, layered hydroxide Ni x M y N Z (OH)2]·[(B a- ) b ·mH2O] or layered oxyhydroxide [Ni x M y N Z OOH], one or more of layered hydroxides [Co x M y N Z (OH)2]·[(B a- ) b ·mH2O], layered oxyhydroxide Co x M y N Z In OOH, M is Ce, Al or Bi, N is one or more of Zn, Ca, Y, Ga, Sb or Yb, and B a- OH - , Cl - 、F - or BO2 - One or more of 0.9≥x≥0.7, y≥0.1, z≥0, x+y+z=1, b>0, m>0, layered hydroxide Ni x M y N Z (OH)2]·[(B a- ) b ·mH2O], layered oxyhydroxide [Ni x M y N ZOOH] wherein M is Ti, Bi or Cr, N is one or more of Ce, Ca, Mg, Co, Y, Zn, Yb or Sb, B a- OH - , Cl - 、F - , BO2 - 、MoO4 2- or WO4 2- One or more of, 0.9≥x≥0.5, y≥0.1, 0.1≥z≥0, x+y+z=1, b>0, m>0.

[0009] A short-process resource recycling method for waste lithium-ion battery ternary positive electrode materials, characterized by the specific steps of:

[0010] Step S1: Discharging the waste ternary lithium-ion batteries fully and then mechanically disassembling them to obtain the waste lithium-ion battery ternary positive electrode materials through mechanical separation, grinding and screening;

[0011] Step S2: adding the waste lithium-ion battery ternary positive electrode material into an alkaline solution containing a persulfate oxidant, wherein the concentration of the persulfate oxidant is 0.5-2.0 mol / L, the alkaline solution is a sodium hydroxide solution or a potassium hydroxide solution, and the concentration of the alkaline substance sodium hydroxide or potassium hydroxide is 1-7 mol / L, stirring and oxidizing at 20-110° C. for 0.5-10 h, filtering the product, washing with deionized water, drying, and sieving to obtain a ternary composite oxide material;

[0012] Step S3: 55wt%-94wt% of ternary composite oxide material, 0wt%-20wt% of functional additives and 5wt%-20wt% of conductive agent are mixed evenly, and then added into a binder aqueous solution prepared with 1wt%-5wt% of binder, and stirred and mixed evenly to obtain active material slurry, and the obtained active material slurry is coated on the positive electrode substrate or wrapped in the positive electrode substrate, and an alkaline secondary battery positive plate is obtained through a film-making process and further assembled into an alkaline secondary battery.

[0013] A short-process resource recycling method for waste lithium-ion battery ternary positive electrode materials, characterized by the specific steps of:

[0014] Step S1: Discharging the waste ternary lithium-ion batteries fully and then mechanically disassembling them to obtain the waste lithium-ion battery ternary positive electrode materials through mechanical separation, grinding and screening;

[0015] Step S2: adding the waste lithium-ion battery ternary positive electrode material into an alkaline solution containing a persulfate oxidant, wherein the concentration of the persulfate oxidant is 0.5-2.0 mol / L, the alkaline solution is a sodium hydroxide solution or a potassium hydroxide solution, and the concentration of the alkaline substance sodium hydroxide or potassium hydroxide is 1-7 mol / L, stirring and oxidizing at 20-110° C. for 0.5-10 h, filtering the product, washing with deionized water, drying, and sieving to obtain a ternary composite oxide material;

[0016] Step S3: adding the ternary composite oxide material to a 0.5-2.5 mol / L sulfur source salt solution, stirring and sulfiding at 40-150° C. for 1-12 h, filtering the product, and washing with deionized water to obtain a sulfided ternary composite oxide material;

[0017] Step S4: 55wt%-94wt% of the sulfurized ternary composite oxide material, 0wt%-20wt% of the functional additive and 5wt%-20wt% of the conductive agent are mixed evenly, and then added to a binder aqueous solution prepared with 1wt%-5wt% of the binder, and stirred and mixed evenly to obtain an active material slurry, and the obtained active material slurry is coated on the positive electrode substrate or wrapped in the positive electrode substrate, and an alkaline secondary battery positive plate is obtained through a film-making process and further assembled into an alkaline secondary battery.

[0018] It is further defined that the conductive agent is one or more of conductive graphite, conductive carbon black, carbon nanotubes, graphene, cobaltous oxide, cobalt hydroxide oxide or titanium oxide, the binder is one or more of polytetrafluoroethylene, sodium carboxymethyl cellulose, styrene-butadiene rubber, polyvinyl alcohol or hydroxypropyl methylcellulose, and the positive electrode substrate is a perforated steel belt, a three-dimensional steel belt, a stainless steel mesh, foamed nickel or foamed iron.

[0019] An alkaline secondary battery comprises a battery housing, a plate group sealed in the battery housing and an electrolyte, wherein the plate group comprises a positive plate, a negative electrode sheet and a separator, and is characterized in that the positive plate is an alkaline secondary battery positive plate prepared by the above-mentioned preparation method, and the negative electrode sheet is a hydrogen storage alloy negative electrode, an iron negative electrode or a zinc negative electrode, preferably a zinc negative electrode.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0021] 1. The present invention provides a new method for the short-process recycling of waste lithium-ion battery ternary positive electrode materials in the battery field. The recycled waste lithium-ion battery ternary positive electrode materials are innovatively used as raw materials, and a composite material suitable for the positive electrode of an alkaline secondary battery is synthesized through chemical oxidation treatment and / or sulfurization treatment. Suitable functional additives are added to further improve its performance, thereby realizing the resource recycling of the material. 2. The process of the present invention is simple and easy to be mass-produced industrially. The material recycling cost is low, the recovery rate is high, and the performance is excellent. 3. The present invention not only proposes a new recycling scheme for waste ternary materials, but also provides a positive electrode with excellent electrical properties for alkaline secondary batteries. The obtained positive electrode has excellent electrochemical properties, showing high capacity performance and good cycle stability. DETAILED DESCRIPTION

[0022] The above contents of the present invention are further described in detail below through examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies implemented based on the above contents of the present invention belong to the scope of the present invention.

[0023] Example 1

[0024] The waste ternary (NCM622) lithium-ion battery was fully discharged and mechanically disassembled, and the waste ternary powder was obtained by mechanical separation, grinding and screening. 10g of the waste ternary powder was added to 100mL of 4M sodium hydroxide solution dissolved with 30g of sodium persulfate, stirred for 80min, filtered, washed, and vacuum dried at 90℃ for 5h to obtain the ternary composite oxide material.

[0025] Layered hydroxide [Co 0.8 Ce 0.15 Zn 0.05 (OH)2]·[(Cl - ) b Preparation of [mH2O] (b = 0.25, m = 2):

[0026] First, cobalt sulfate, cerium sulfate and zinc sulfate are mixed in a molar ratio of Co / Ce / Zn=0.8 / 0.15 / 0.05 and then prepared at 25°C to form a composite salt solution with a molar concentration of 1.2 mol / L; potassium hydroxide is dissolved in deionized water to prepare an alkaline solution with a molar concentration of 2.5 mol / L; the alkaline solution is added dropwise to the mixed salt solution at 25°C using a peristaltic pump, and the reaction is continuously stirred until the pH of the reaction suspension reaches 10. After the reaction is completed, the obtained suspension is reacted at 50°C for 10 hours, cooled to room temperature, filtered, washed, and dried to obtain a powder; the obtained powder is transferred to a sodium chloride solution with a molar concentration of 0.5 mol / L, treated at 120°C for 6 hours under the protection of inert gas nitrogen, filtered, washed, and dried to obtain a layered hydroxide [Co 0.8Ce 0.15 Zn 0.05 (OH)2]·[(Cl - ) b ·mH2O](b=0.25,m=2).

[0027] The prepared ternary composite oxide material 0.77g, layered hydroxide [Co 0.8 Ce 0.15 Zn 0.05 (OH)2]·[(Cl - ) b ·mH2O] 0.1g, 0.03g strontium titanate, 0.1g conductive carbon black, 0.07g HPMC with a mass concentration of 2.5% and 0.01g PTFE aqueous solution with a mass concentration of 60% are mixed evenly to prepare positive electrode slurry. The slurry is coated on the foam nickel base tape by slurry drawing, and the foam nickel positive plate is prepared after drying, cutting, cleaning powder and welding the connecting plate for use.

[0028] The prepared positive electrode plate and the zinc negative electrode plate are sandwiched with a special zinc-nickel battery separator, and the plates are stacked and assembled into a battery plate group, which is then loaded into a simulated battery shell. After activation with alkaline solution, a saturated zinc chloride 7 mol / L KOH solution is injected as an electrolyte to assemble a semi-sealed alkaline secondary battery.

[0029] Example 2

[0030] After the waste ternary (NCM523) lithium-ion battery is fully discharged, it is mechanically disassembled, and the waste ternary powder is obtained by mechanical separation, grinding and screening. 10g of waste ternary powder is added to 100mL of 2M sodium hydroxide solution dissolved with 30g of sodium persulfate, stirred for 120min, filtered, washed, and vacuum dried at 90℃ for 5h to obtain a ternary composite oxide material. Sodium sulfide is dissolved in deionized water to prepare a 1.0mol / L sulfur source salt solution, 20g of ternary composite oxide material is added to 100mL of sulfur source salt solution, stirred at 50℃ for 5h, filtered, dried at 80℃ for 6h, crushed, and screened to obtain a sulfurized ternary composite oxide material.

[0031] Partially oxidized layered hydroxide Ni 0.8 Bi 0.1 Yb 0.1 (OH)2·[(A a- ) b ·mH2O](A a- =OH - , b = 0.2, m = 2);

[0032] First, nickel nitrate, bismuth nitrate and aluminum chloride are mixed in a molar ratio of Ni / Bi / Al=0.8 / 0.1 / 0.1, and then prepared at 25°C to form a composite salt solution with a molar concentration of 0.5 mol / L; potassium hydroxide is dissolved in deionized water to prepare an alkaline solution with a molar concentration of 3 mol / L; the alkaline solution is added dropwise to the mixed salt solution at 25°C using a peristaltic pump, and is continuously stirred until the pH of the reaction suspension reaches 7.5. After the reaction is completed, the obtained suspension is reacted at 80°C for 20 hours, cooled to room temperature, filtered, washed, and dried to obtain a powder; the obtained powder is transferred to a sodium hydroxide solution with a molar concentration of 0.5 mol / L, treated at 150°C for 5 hours under the protection of inert gas nitrogen, filtered, washed, and dried to obtain a layered hydroxide. Then 10 g of layered hydroxide was added to 100 mL of 1 M sodium hydroxide solution containing 10 g of sodium persulfate, stirred for 40 min, filtered, washed, and dried under vacuum at 90 ° C for 5 h to obtain partially oxidized layered hydroxide Ni 0.8 Bi 0.1 Yb 0.1 (OH)2·[(A a- ) b ·mH2O](A a- =OH - , b=0.2, m=2).

[0033] Partially oxidized layered hydroxides [Co 0.8 Ce 0.15 Zn 0.05 (OH)2]·[(Cl - ) b Preparation of [mH2O] (b = 0.2, m = 2):

[0034] First, cobalt chloride, cerium chloride and zinc chloride are mixed in a molar ratio of Co / Ce / Al=0.8 / 0.15 / 0.05 and then prepared at 25°C to form a composite salt solution with a molar concentration of 1.0 mol / L; potassium hydroxide is dissolved in deionized water to prepare an alkaline solution with a molar concentration of 2.0 mol / L; the alkaline solution is added dropwise to the mixed salt solution at 25°C using a peristaltic pump, and the reaction is continuously stirred until the pH of the reaction suspension reaches 9.5. After the reaction is completed, the obtained suspension is reacted at 90°C for 10 hours, cooled to room temperature, filtered, washed, and dried to obtain a powder; the obtained powder is transferred to a sodium chloride solution with a molar concentration of 1.0 mol / L, treated at 100°C for 1 hour under the protection of inert gas nitrogen, filtered, washed, and dried to obtain a layered hydroxide. Then, 10 g of the layered hydroxide was added to 100 mL of 2.5 M sodium hydroxide solution containing 15 g of sodium persulfate, stirred for 50 min, filtered, washed, and dried under vacuum at 90 ° C for 5 h to obtain a partially oxidized layered hydroxide [Co 0.75 Al0.15 Ga 0.05 Sb 0.05 (OH)2]·[(Cl - ) b ·mH2O](b=0.2,m=2).

[0035] The prepared sulfided ternary composite oxide material 0.58 g, partially oxidized layered hydroxide Ni 0.8 Bi 0.1 Yb 0.1 (OH)2·[(A a- ) b ·mH2O]0.2g, partially oxidized layered hydroxide [Co 0.8 Ce 0.15 Zn 0.05 (OH)2]·[(Cl - ) b ·mH2O] 0.05g, calcium titanate 0.02g, conductive graphite 0.1g, cobalt oxide 0.05g, 2.5% HPMC 0.07g, 60% PTFE aqueous solution 0.01g and 2% SBR aqueous solution 0.01g were mixed evenly to prepare positive electrode slurry. The slurry was coated on the foamed nickel by slurry drawing, and the positive plate was prepared after drying, cutting, powder cleaning and welding of connecting plates.

[0036] The prepared positive electrode plate and the conventional zinc negative electrode plate are sandwiched with a special separator for zinc-nickel batteries, and the plates are stacked and assembled into a battery plate group, which is then loaded into a simulated battery shell. After activation with alkaline solution, a 7 mol / L KOH solution of saturated zinc chloride is injected as an electrolyte to assemble a semi-sealed alkaline secondary battery.

[0037] Example 3

[0038] After the waste ternary (NCM811) lithium-ion battery is fully discharged, it is mechanically disassembled, and the waste ternary powder is obtained by mechanical separation, grinding and screening. Then, 10g of the waste ternary powder is added to 100mL of 3M sodium hydroxide solution dissolved with 40g of sodium persulfate and 5g of potassium persulfate, stirred for 5h, filtered, washed, and vacuum dried at 90℃ for 5h to obtain a ternary composite oxide material. Sodium sulfide is dissolved in deionized water to prepare a 0.5mol / L sulfur source salt solution, 20g of the ternary composite oxide material is added to 100mL of the sulfur source salt solution, stirred at 70℃ for 12h, filtered, dried at 80℃ for 6h, crushed, and screened to obtain a sulfurized ternary composite oxide material.

[0039] Partially sulfided layered hydroxide Ni 0.7 Ti 0.2 Y 0.1 (OH)2·[(Aa- ) b ·mH2O](A a- =F - , b = 0.15, m = 2) preparation:

[0040] First, nickel chloride, titanium sulfate and yttrium chloride are mixed in a molar ratio of Ni / Ti / Y=0.7 / 0.2 / 0.1 and then prepared at 25°C to form a composite salt solution with a molar concentration of 1.8 mol / L; potassium hydroxide is dissolved in deionized water to prepare an alkaline solution with a molar concentration of 1.5 mol / L; the alkaline solution is added dropwise to the mixed salt solution at 25°C using a peristaltic pump, and stirred continuously until the pH of the reaction suspension reaches 9. After the reaction is completed, the obtained suspension is reacted at 90°C for 10 hours, cooled to room temperature, filtered, washed, and dried to obtain a powder; the obtained powder is transferred to a sodium fluoride solution with a molar concentration of 1.0 mol / L, treated at 90°C for 10 hours under the protection of inert gas nitrogen, filtered, washed, and dried to obtain a layered hydroxide. Then, 10 g of the layered hydroxide is added to 100 mL of 0.15 M sodium sulfide solution, stirred for 40 minutes, filtered, washed, and dried to obtain a partially sulfided Ni 0.7 Ti 0.2 Y 0.1 (OH)2·[(A a- ) b ·mH2O](A a- =F - , b=0.15, m=2).

[0041] Layered oxyhydroxide [Co 0.8 Ce 0.1 Zn 0.05 Ca 0.05 OOH] is [Co 0.8 Ce 0.1 Zn 0.05 Ca 0.05 ]·[(Cl - ) b ·mH2O] material is a precursor, which is prepared by chemical oxidation of persulfate under alkaline solution conditions.

[0042] 0.63 g of the prepared sulfided ternary composite oxide material and partially sulfided layered hydroxide Ni 0.7 Ti 0.2 Y 0.1 (OH)2·[(A a- ) b ·mH2O]0.15g, layered oxyhydroxide [Co 0.8 Ce 0.1 Zn 0.05 Ca 0.05[0.1g of OOH], 0.01g of barium titanate, 0.1g of conductive graphite, 0.01g of carbon nanotubes, 0.07g of CMC with a mass concentration of 2.5% and 0.01g of PTFE aqueous solution with a mass concentration of 60% are mixed evenly to prepare a positive electrode slurry. The slurry is coated on a foam nickel base tape by a slurry drawing method, and after drying, cutting, cleaning powder, and welding the connecting plate, a foam nickel positive electrode plate is prepared for use.

[0043] The prepared positive electrode plate and the conventional zinc negative electrode plate are sandwiched with a special separator for zinc-nickel batteries, and the plates are stacked and assembled into a battery plate group, which is then loaded into a simulated battery shell. After activation with alkaline solution, a 7 mol / L KOH solution of saturated zinc chloride is injected as an electrolyte to assemble a semi-sealed alkaline secondary battery.

[0044] Example 4

[0045] The waste ternary (LiNi 0.8 Co 0.15 Al 0.05 O2) After the lithium-ion battery is fully discharged, it is mechanically disassembled, and the waste ternary powder is obtained by mechanical separation, grinding and screening. Then, 10g of the waste ternary powder is added to 100mL of 4M sodium hydroxide solution dissolved with 50g of sodium persulfate, stirred for 1h, filtered, washed, and vacuum dried at 80℃ for 6h to obtain a ternary composite oxide material. Sodium sulfide is dissolved in deionized water to prepare a 1.2mol / L sulfur source salt solution, 20g of the ternary composite oxide material is added to 100mL of the sulfur source salt solution, stirred at 50℃ for 12h, filtered, dried at 80℃ for 6h, crushed, and screened to obtain a sulfurized ternary composite oxide material.

[0046] Partially oxidized layered hydroxide Ni 0.7 Cr 0.2 Ce 0.06 Mg 0.04 (OH)2·[(A a- ) b ·mH2O](A a- =Cl - , b = 0.2, m = 2) preparation:

[0047] First, nickel chloride, chromium chloride, cerium chloride and yttrium chloride are mixed in a molar ratio of Ni / Cr / Ce / Mg=0.7 / 0.2 / 0.06 / 0.04 and prepared at 25°C to form a composite salt solution with a molar concentration of 1.4 mol / L; potassium hydroxide is dissolved in deionized water to prepare an alkaline solution with a molar concentration of 3.0 mol / L; the alkaline solution is added dropwise to the mixed salt solution at 25°C using a peristaltic pump, and the reaction is continuously stirred until the pH of the reaction suspension reaches 10. After the reaction is completed, the obtained suspension is reacted at 90°C for 10 hours, cooled to room temperature, filtered, washed, and dried to obtain a powder; the obtained powder is transferred to a sodium chloride solution with a molar concentration of 1.0 mol / L, treated at 120°C for 1 hour under the protection of inert gas nitrogen, filtered, washed, and dried to obtain a layered hydroxide. Then, 10 g of the layered hydroxide was added to 100 mL of 2.5 M sodium hydroxide solution containing 15 g of sodium persulfate, stirred for 50 min, filtered, washed, and dried under vacuum at 90 °C for 5 h to obtain partially oxidized layered hydroxide Ni 0.7 Cr 0.2 Ce 0.06 Mg 0.04 (OH)2·[(A a- ) b ·mH2O](A a- =Cl - , b=0.2, m=2).

[0048] Partially oxidized layered hydroxides [Co 0.75 Al 0.15 Ga 0.05 Sb 0.05 (OH)2]·[(Cl - ) b Preparation of [mH2O] (b = 0.2, m = 2):

[0049] First, cobalt chloride, aluminum chloride, gallium chloride and antimony chloride are mixed in a molar ratio of Co / Al / Ga / Sb=0.75 / 0.15 / 0.05 / 0.05, and then prepared at 25°C to form a composite salt solution with a molar concentration of 1.0 mol / L; potassium hydroxide is dissolved in deionized water to prepare an alkaline solution with a molar concentration of 2.0 mol / L; the alkaline solution is added dropwise to the mixed salt solution at 25°C using a peristaltic pump, and the reaction is continuously stirred until the pH of the reaction suspension reaches 9.5. After the reaction is completed, the obtained suspension is reacted at 90°C for 10 hours, cooled to room temperature, filtered, washed, and dried to obtain a powder; the obtained powder is transferred to a sodium chloride solution with a molar concentration of 1.0 mol / L, treated at 100°C for 1 hour under the protection of inert gas nitrogen, filtered, washed, and dried to obtain a layered hydroxide. Then, 10 g of the layered hydroxide was added to 100 mL of 2.5 M sodium hydroxide solution containing 15 g of sodium persulfate, stirred for 50 min, filtered, washed, and dried under vacuum at 90 °C for 5 h to obtain a partially oxidized layered hydroxide [Co 0.75 Al 0.15 Ga 0.05 Sb 0.05 (OH)2]·[(Cl - ) b ·mH2O](b=0.2,m=2).

[0050] 0.60 g of the prepared sulfided ternary composite oxide material and partially oxidized layered hydroxide Ni 0.7 Cr 0.2 Ce 0.06 Mg 0.04 (OH)2·[(A a- ) b ·mH2O]0.2g, partially oxidized layered hydroxide [Co 0.75 Al 0.15 Ga 0.05 Sb 0.05 (OH)2]·[(Cl - ) b ·mH2O] 0.08g, 0.01g strontium titanate, 0.01g calcium titanate, 0.1g conductive graphite, 0.01g titanium oxide, 0.07g CMC with a mass concentration of 2.5% and 0.01g PTFE aqueous solution with a mass concentration of 60% are mixed evenly to prepare positive electrode slurry. The slurry is coated on the foam nickel base tape by slurry drawing, and the foam nickel positive plate is prepared after drying, cutting, cleaning powder and welding the connecting plate for use.

[0051] The prepared positive electrode plate and the conventional zinc negative electrode plate are sandwiched with a special separator for zinc-nickel batteries, and the plates are stacked and assembled into a battery plate group, which is then loaded into a simulated battery shell. After activation with alkaline solution, a 7 mol / L KOH solution saturated with zinc oxide is injected as an electrolyte to assemble a semi-sealed alkaline secondary battery.

[0052] Example 5

[0053] The positive electrode plate prepared in Example 1 was selected as the positive electrode.

[0054] Preparation of negative electrode plate of hydrogen storage alloy steel strip: 78g of AB5 type hydrogen storage alloy powder, 5g of nickel powder, 5g of conductive carbon black, 10g of 2.5% PVA solution and 2g of 2% SBR aqueous solution were mixed evenly to prepare negative electrode slurry. A layer of slurry was applied on the nickel-plated steel strip by slurry drawing, and after drying, cutting and welding the connecting plate, the negative electrode plate of hydrogen storage alloy steel strip was prepared for use.

[0055] Preparation of electrolyte: Potassium hydroxide and lithium hydroxide are added to deionized water to prepare an alkaline solution with a total molar concentration of 6M.

[0056] The positive and negative plates of the battery are separated by a sulfonated polypropylene diaphragm with a thickness of about 0.4 mm. The prepared nickel foam positive plate and hydrogen storage alloy steel strip negative plate are placed in a diaphragm bag, stacked and assembled into a battery plate group, which is then placed in a square battery shell, activated with alkaline solution, and sealed to assemble into an alkaline secondary battery.

[0057] Example 6

[0058] The positive electrode plate prepared in Example 2 was selected as the positive electrode, and the iron electrode was selected as the negative electrode.

[0059] Preparation of iron negative electrode: 70g of ferroferric oxide powder, 15g of ferrous sulfide, 10g of conductive graphite, 5g of bismuth sulfide, 8g of 2.5% CMC solution and 2g of 60% PTFE aqueous solution are mixed evenly to prepare negative electrode slurry; a layer of slurry is coated on a nickel-plated steel strip by slurry drawing, and after drying, cutting and welding of the connecting plate, a hydrogen storage alloy steel strip negative electrode plate is obtained for use.

[0060] Preparation of electrolyte: Potassium hydroxide and lithium hydroxide were dissolved in deionized water to prepare a solution with a total molar concentration of 6.5 M. 50 g of sodium sulfide was added to 1000 mL of the above solution.

[0061] The separators of the positive and negative plates of the battery are made of polypropylene needle-punched non-woven fabric with a thickness of about 0.8 mm and a polypropylene composite separator. The prepared positive plate, iron negative plate and composite separator are assembled into an electrode group, loaded into a square battery shell, filled with alkaline electrolyte for activation, and then sealed to assemble into an alkaline secondary battery.

[0062] Battery performance test: The battery made by using specific examples 1-6 was activated by 0.2C, charged at 0.2C for 6 hours, and then the battery was left for 30 minutes to measure the capacity performance of the positive electrode material. Battery cycle performance test: The battery made by the positive electrode material prepared by examples 1-6 was subjected to constant current and constant voltage charge and discharge 1C test at an ambient temperature of 25°C. The battery electrical performance test results are listed in Table 1.

[0063] Table 1 Battery charge and discharge performance test

[0064]

[0065] It can be seen from the above test results that a method for resource recycling of waste lithium-ion battery ternary positive electrode materials provided by the present invention is adopted. The recycled waste ternary positive electrode materials are used as raw materials, and through chemical oxidation treatment and sulfurization treatment, a composite material suitable for the positive electrode of an alkaline secondary battery is synthesized, and suitable functional additives are added to further improve its performance, thereby realizing resource recycling of the material. The method of the present invention not only realizes the secondary utilization of waste ternary positive electrode material resources, reduces the waste of resources and environmental pollution problems caused by waste lithium-ion batteries, but also provides a positive electrode material with excellent performance for alkaline secondary batteries. The positive electrode active material prepared by this technical solution has a high gram capacity and excellent cycle performance, so that the prepared alkaline secondary battery has the advantage of a long cycle life.

[0066] The above embodiments describe the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of protection of the present invention.

Claims

1. A short-process resource recycling method for waste lithium-ion battery ternary positive electrode materials, characterized in that The specific process is: the recycled waste lithium-ion battery ternary positive electrode material is subjected to chemical oxidation treatment in an alkaline solution dissolved with a persulfate oxidant to obtain a ternary composite oxide material, and then the ternary composite oxide material is used as an alkaline secondary battery positive electrode active material to prepare an alkaline secondary battery positive electrode plate and used to assemble an alkaline secondary battery; the waste lithium-ion battery ternary positive electrode material is LiNi x Co y Mn z O2 or LiNi x Co y Al z One or more of O2, LiNi x Co y Mn z In O2, x+y+z=1, x>0.3, y>0, z>0, LiNi x Co y Al z In O2, x+y+z=1, x>0.5, y>0, z>0, and the corresponding ternary composite oxide material is Ni x Co y Mn z O2 or Ni x Co y Al z One or more of O2, Ni x Co y Mn z In O2, x+y+z=1, x>0.3, y>0, z>0, Ni x Co y Al z In O2, x+y+z=1, x>0.5, y>0, z>0, and the persulfate oxidant is one or more of ammonium persulfate, potassium persulfate or sodium persulfate.

2. The method for recycling waste lithium-ion battery ternary cathode materials in a short process according to claim 1, characterized in that: The ternary positive electrode material of the waste lithium-ion battery is 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 or LiNi 0.8 Co 0.15 Al 0.05 O2 one or more; the corresponding ternary composite oxide material is Ni 0.5 Co 0.2 Mn 0.3 O2, Ni 0.6 Co 0.2 Mn 0.2 O2, Ni 0.8 Co 0.1 Mn 0.1 O2 or Ni 0.8 Co 0.15 Al 0.05 One or more of O2.

3. The short-process resource recycling method for waste lithium-ion battery ternary positive electrode materials according to claim 1 is characterized in that: The ternary composite oxide material is chemically sulfurized in a sulfur source salt solution to obtain a sulfurized ternary composite oxide material, and the sulfurized ternary composite oxide material is then used as an alkaline secondary battery positive electrode active material to prepare an alkaline secondary battery positive electrode plate and to assemble an alkaline secondary battery, wherein the sulfur source salt is one or more of sodium sulfide, thiourea or thiopropionamide.

4. The method for recycling waste lithium-ion battery ternary cathode materials in a short process according to claim 1 or 3, characterized in that: When preparing the positive electrode plate of the alkaline secondary battery, a functional additive is added to the positive electrode active material of the alkaline secondary battery. The functional additive is nickel molybdate, nickel tungstate, nickel oxyhydroxide, chromium oxide, chromium hydroxide, strontium oxide, strontium hydroxide, layered hydroxide [Co x M y N Z (OH)2]·[(B a- ) b ·mH2O], layered oxyhydroxide Co x M y N Z OOH, layered hydroxide Ni x M y N Z (OH)2]·[(B a- ) b ·mH2O] or layered oxyhydroxide [Ni x M y N Z OOH], one or more of layered hydroxides [Co x M y N Z (OH)2]·[(B a- ) b ·mH2O], layered oxyhydroxide Co x M y N Z In OOH, M is Ce, Al or Bi, N is one or more of Zn, Ca, Y, Ga, Sb or Yb, and B a- OH - , Cl - 、F - or BO2 - One or more of 0.9≥x≥0.7, y≥0.1, z≥0, x+y+z=1, b>0, m>0, layered hydroxide Ni x M y N Z (OH)2]·[(B a- ) b ·mH2O], layered oxyhydroxide [Ni x M y N Z OOH] wherein M is Ti, Bi or Cr, N is one or more of Ce, Ca, Mg, Co, Y, Zn, Yb or Sb, B a- OH - , Cl - 、F - , BO2 - 、MoO4 2- or WO4 2- One or more of, 0.9≥x≥0.5, y≥0.1, 0.1≥z≥0, x+y+z=1, b>0, m>0.

5. The method for recycling waste lithium-ion battery ternary cathode materials in a short process according to claim 1, characterized in that The specific steps are: Step S1: Discharging the waste ternary lithium-ion batteries fully and then mechanically disassembling them to obtain the waste lithium-ion battery ternary positive electrode materials through mechanical separation, grinding and screening; Step S2: adding the waste lithium-ion battery ternary positive electrode material into an alkaline solution containing a persulfate oxidant, wherein the concentration of the persulfate oxidant is 0.5-2.0 mol / L, the alkaline solution is a sodium hydroxide solution or a potassium hydroxide solution, and the concentration of the alkaline substance sodium hydroxide or potassium hydroxide is 1-7 mol / L, stirring and oxidizing at 20-110° C. for 0.5-10 h, filtering the product, washing with deionized water, drying, and sieving to obtain a ternary composite oxide material; Step S3: 55wt%-94wt% of ternary composite oxide material, 0wt%-20wt% of functional additives and 5wt%-20wt% of conductive agent are mixed evenly, and then added into a binder aqueous solution prepared with 1wt%-5wt% of binder, and stirred and mixed evenly to obtain active material slurry, and the obtained active material slurry is coated on the positive electrode substrate or wrapped in the positive electrode substrate, and an alkaline secondary battery positive plate is obtained through a film-making process and further assembled into an alkaline secondary battery.

6. The method for recycling waste lithium-ion battery ternary cathode materials in a short process according to claim 4, characterized in that The specific steps are: Step S1: Discharging the waste ternary lithium-ion batteries fully and then mechanically disassembling them to obtain the waste lithium-ion battery ternary positive electrode materials through mechanical separation, grinding and screening; Step S2: adding the waste lithium-ion battery ternary positive electrode material into an alkaline solution containing a persulfate oxidant, wherein the concentration of the persulfate oxidant is 0.5-2.0 mol / L, the alkaline solution is a sodium hydroxide solution or a potassium hydroxide solution, and the concentration of the alkaline substance sodium hydroxide or potassium hydroxide is 1-7 mol / L, stirring and oxidizing at 20-110° C. for 0.5-10 h, filtering the product, washing with deionized water, drying, and sieving to obtain a ternary composite oxide material; Step S3: adding the ternary composite oxide material to a 0.5-2.5 mol / L sulfur source salt solution, stirring and sulfiding at 40-150° C. for 1-12 h, filtering the product, and washing with deionized water to obtain a sulfided ternary composite oxide material; Step S4: 55wt%-94wt% of the sulfurized ternary composite oxide material, 0wt%-20wt% of the functional additive and 5wt%-20wt% of the conductive agent are mixed evenly, and then added to a binder aqueous solution prepared with 1wt%-5wt% of the binder, and stirred and mixed evenly to obtain an active material slurry, and the obtained active material slurry is coated on the positive electrode substrate or wrapped in the positive electrode substrate, and an alkaline secondary battery positive plate is obtained through a film-making process and further assembled into an alkaline secondary battery.

7. The method for recycling waste lithium-ion battery ternary cathode materials in a short process according to claim 5 or 6, characterized in that: The conductive agent is one or more of conductive graphite, conductive carbon black, carbon nanotubes, graphene, cobaltous oxide, cobalt hydroxide oxide or titanium oxide, the binder is one or more of polytetrafluoroethylene, sodium carboxymethyl cellulose, styrene-butadiene rubber, polyvinyl alcohol or hydroxypropyl methylcellulose, and the positive electrode substrate is a perforated steel belt, a three-dimensional steel belt, a stainless steel mesh, foamed nickel or foamed iron.

8. An alkaline secondary battery, comprising a battery housing, a plate group sealed in the battery housing, and an electrolyte, wherein the plate group comprises a positive plate, a negative plate, and a separator, characterized in that: The positive electrode plate is an alkaline secondary battery positive electrode plate prepared by the method of claim 1 or 3, and the negative electrode sheet is a hydrogen storage alloy negative electrode, an iron negative electrode or a zinc negative electrode.

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