Method for preparing aqueous zinc ion battery by recycling retired lithium ion battery and aqueous zinc ion battery

Abstract

The invention provides a method for preparing a water-based zinc ion battery by recycling a retired lithium ion battery and the water-based zinc ion battery, and belongs to the technical field of water-based zinc ion batteries and recycling and regeneration. The preparation method comprises the following steps: firstly, mixing a retired lithium manganate positive electrode material and a sulfuric acid solution, and performing hydrothermal reaction to obtain manganese dioxide and a washing solution; then, the washing liquid is matched with zinc sulfate to prepare electrolyte; and finally, taking manganese dioxide as a positive electrode, preparing electrolyte from manganese sulfate and zinc sulfate, and preparing the aqueous zinc ion battery from zinc foil. The manganese dioxide solution and the manganese sulfate solution can be obtained by regulating and controlling the reaction temperature and the reaction time, the retired lithium ion battery is recycled to prepare the aqueous zinc ion battery, and the recovery rate of manganese is almost 100%.

Description

Technical Field

[0001] The present invention relates to the field of aqueous zinc ion batteries and recycling and regeneration technology, and in particular to a method for preparing aqueous zinc ion batteries by recycling retired lithium ion batteries and the aqueous zinc ion battery. Background Art

[0002] At present, research on the recycling of retired lithium-ion batteries mainly includes pyrometallurgy and hydrometallurgy. Pyrometallurgy is the recovery of metals in the form of alloys through high-temperature roasting. This method has a simple process route, but high energy consumption and low metal recovery rate. Hydrometallurgy is the leaching of metals into the solution in the form of ions, and then recovering the metals through separation and purification processes. This process has the characteristics of low energy consumption, high purity and low recycling cost. However, a large amount of extractants and precipitants are required in the separation and purification process of each metal, and the recovery process is complicated. In addition, the process will produce a large amount of acid and alkaline wastewater, resulting in secondary pollution. The direct recovery process developed in recent years directly regenerates the positive electrode materials of lithium-ion batteries by supplementing the missing components of the materials and repairing the structural defects of the materials, thereby realizing the "closed-loop" application of waste lithium-ion batteries.

[0003] Since the commercialization of lithium-ion batteries (LIBs) in 1990, the global demand for high-energy-density energy storage devices has grown rapidly. However, with the popularization of lithium-ion batteries, the safety of lithium-ion batteries has attracted increasing attention due to the possibility of thermal runaway of electrode materials in highly flammable and volatile organic electrolytes, resulting in safety accidents. Rechargeable aqueous zinc-ion batteries have become one of the promising candidates for advanced energy storage systems due to their low cost, inherent safety and environmental friendliness. In addition, compared with flammable organic electrolytes, non-flammable aqueous zinc-ion electrolytes have advantages such as stability, reversibility and non-toxicity. Aqueous zinc-ion batteries can better meet the economic, safety and high-performance requirements of large-scale energy storage equipment, showing great potential for practical applications. Summary of the Invention

[0004] The object of the present invention is to provide a method for recycling retired lithium-ion batteries to prepare aqueous zinc-ion batteries and an aqueous zinc-ion battery, so as to solve the technical problems existing in the prior art in the recycling of retired lithium-ion battery positive electrode materials, such as complex process, high energy consumption, low utilization rate of waste gas and waste liquid, and low safety of lithium-ion batteries.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for recycling retired lithium-ion batteries to prepare aqueous zinc-ion batteries, comprising the following steps:

[0007] Step 1) mixing the retired lithium manganese oxide positive electrode material and the sulfuric acid solution and performing a hydrothermal reaction to obtain manganese dioxide and a washing solution;

[0008] Step 2), measure the manganese content in the washing liquid, and mix the washing liquid with zinc sulfate to prepare an aqueous electrolyte;

[0009] Step 3), mix manganese dioxide, conductive carbon and polyvinylidene fluoride, coat on a foil, and dry to obtain a positive electrode sheet, and combine the positive electrode sheet, the aqueous electrolyte and a zinc foil to obtain an aqueous zinc ion battery.

[0010] Further, in step 1), the mass-volume ratio of the retired lithium manganate positive electrode material and the sulfuric acid solution is 2.0-3.0g: 0.5-1mol / L.

[0011] Further, in step 1), the mixing is carried out under stirring, the stirring speed is 700-1000rpm, and the stirring time is 1-3h.

[0012] Further, in step 1), the temperature of the hydrothermal reaction is 140-220℃, and the hydrothermal reaction time is 16-32h.

[0013] Further, in step 2), the molar ratio of manganese ions and zinc ions in the aqueous electrolyte is 0.1:1-2.

[0014] Further, in step 3), the mass ratio of manganese dioxide, conductive carbon and polyvinylidene fluoride is 6-10:1-3:1-2.

[0015] Further, in step 3), the foil includes a titanium foil.

[0016] Further, in step 3), the drying temperature is 70-100℃, and the drying time is 10-15h.

[0017] The application also provides an aqueous zinc ion battery prepared by the above method.

[0018] The application has the following advantages:

[0019] The recycling method provided by the application has the advantages of simple process, low energy consumption compared with the pyrometallurgical process (complex process and high energy consumption), low process cost and no waste liquid compared with the hydrometallurgical process (waste liquid and additional chemicals).

[0020] The application can realize 100% recovery of manganese, use manganese dioxide recovered from the retired lithium ion battery positive electrode material as the positive electrode, and use the unrecycled manganese in the form of manganese sulfate for electrolyte preparation, thereby realizing efficient utilization of manganese.

[0021] The present invention recycles retired lithium-ion batteries into aqueous zinc-ion batteries with high energy density and high safety performance, solving the technical problems of aqueous zinc-ion batteries with high cost, low energy density and low safety performance.

[0022] The retired lithium-ion battery recycling method provided by the present invention has low requirements for synthesis equipment, is simple to operate, has no special requirements for production process, and is environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a process flow chart of the present invention;

[0024] Figure 2 This is the XRD pattern of manganese dioxide obtained in Example 1;

[0025] Figure 3 The SEM images of the manganese dioxide obtained in Example 1 are shown in Figure 1, with the left image at a magnification of 1W and the right image at a magnification of 2W.

[0026] Figure 4 This is the electrochemical performance diagram of the aqueous zinc ion battery obtained in Example 1. DETAILED DESCRIPTION

[0027] The present invention provides a method for recycling retired lithium-ion batteries to prepare aqueous zinc-ion batteries, comprising the following steps:

[0028] Step 1) mixing the retired lithium manganate positive electrode material and the sulfuric acid solution and performing a hydrothermal reaction to obtain manganese dioxide and a washing solution;

[0029] Step 2), measuring the manganese content in the washing liquid, and mixing the washing liquid with zinc sulfate to obtain an aqueous electrolyte;

[0030] Step 3) Mix manganese dioxide, conductive carbon and polyvinylidene fluoride and apply the mixture on a foil, dry it to obtain a positive electrode sheet, and combine the positive electrode sheet, aqueous electrolyte and zinc foil to obtain an aqueous zinc ion battery.

[0031] In the present invention, in step 1), the mass volume ratio of the retired lithium manganese oxide positive electrode material and the sulfuric acid solution is 2.0-3.0 g:0.5-1 mol / L, preferably 2.2-2.8 g:0.5-1 mol / L, and more preferably 2.715 g:1 mol / L.

[0032] In the present invention, in step 1), after the hydrothermal reaction is completed, the mixture is filtered to obtain black precipitated manganese dioxide, which is washed with deionized water, and the filtrate is added to the washing liquid.

[0033] In the present application, in step 1), the mixing is carried out under stirring, the stirring speed is 700-1000 rpm, preferably 800-900 rpm, and further preferably 850 rpm; the stirring time is 1-3 h, preferably 2 h.

[0034] In the present application, in step 1), the temperature of the hydrothermal reaction is 140-220℃, preferably 150-200℃, and further preferably 180℃; the time of the hydrothermal reaction is 16-32 h, preferably 18-28℃, and further preferably 25℃.

[0035] In the present application, in step 2), the molar ratio of manganese ions to zinc ions in the aqueous electrolyte is 0.1:1-2, preferably 0.1:2.

[0036] In the present application, in step 2), the concentration of manganese ions in the washing liquid is preferably tested by ICP.

[0037] In the present application, in step 3), the mass ratio of manganese dioxide, conductive carbon and polyvinylidene fluoride is 6-10:1-3:1-2, preferably 7:3:1.

[0038] In the present application, in step 3), the manganese dioxide, conductive carbon and polyvinylidene fluoride are mixed to form a slurry which is coated on the foil.

[0039] In the present application, in step 3), the foil is preferably a titanium foil.

[0040] In the present application, in step 3), the temperature of the drying is 70-100℃, preferably 80℃; the time of the drying is 10-15 h, preferably 12 h.

[0041] In the present application, in step 3), the drying is preferably carried out in a vacuum oven.

[0042] The present application also provides a water-based zinc ion battery prepared by the above method.

[0043] The technical solutions provided by the present application will be described in detail below in conjunction with the examples, but they should not be understood as limiting the scope of protection of the present application.

[0044] Example 1

[0045] 2.715 g of retired lithium manganese oxide positive electrode material was mixed with 20 mL of 1 mol / L sulfuric acid solution, stirred at 800 rpm for 2 h, and then transferred to a reactor for hydrothermal reaction at 180 ° C for 24 h. After the reaction was completed, the obtained black precipitated manganese dioxide was filtered and washed with deionized water to obtain manganese dioxide and washing liquid (the filtrate was incorporated into the washing liquid). The manganese dioxide was dried at 120 ° C for 24 h, and then a slurry was prepared at a mass ratio of manganese dioxide, conductive carbon and PVDF of 7:2:1, coated on titanium foil, and fully dried in a vacuum oven at 80 ° C for 12 h to prepare a positive electrode sheet;

[0046] The concentration of Mn ions in the washing solution was tested by ICP, and then an aqueous zinc ion battery electrolyte was prepared according to a molar ratio of manganese sulfate to zinc sulfate of 0.1:2. The obtained positive electrode sheet, aqueous zinc ion battery electrolyte and zinc foil were made into button batteries.

[0047] Example 2

[0048] 2.715 of retired lithium manganese oxide positive electrode material was mixed with 20 mL of 0.5 mol / L sulfuric acid solution, stirred at 800 rpm for 2 hours, and then transferred to a reactor for hydrothermal reaction at 160°C for 32 hours. After the reaction was completed, the obtained black precipitated manganese dioxide was filtered and washed with deionized water to obtain manganese dioxide and washing liquid (the filtrate was incorporated into the washing liquid). The manganese dioxide was dried at 120°C for 24 hours, and then a slurry was prepared with a mass ratio of manganese dioxide, conductive carbon and PVDF of 7:2:1, coated on titanium foil, and fully dried in a vacuum oven at 80°C for 12 hours to prepare a positive electrode sheet;

[0049] The concentration of Mn ions in the washing solution was tested by ICP, and then an aqueous zinc ion battery electrolyte was prepared according to a molar ratio of manganese sulfate to zinc sulfate of 0.1:1. The obtained positive electrode sheet, aqueous zinc ion battery electrolyte and zinc foil were made into button batteries.

[0050] Example 3

[0051] 3 g of retired lithium manganese oxide positive electrode material was mixed with 20 mL of 1 mol / L sulfuric acid solution, stirred at 800 rpm for 2 h, and then transferred to a reactor for hydrothermal reaction at 220 ° C for 16 h. After the reaction was completed, the obtained black precipitated manganese dioxide was filtered and washed with deionized water to obtain manganese dioxide and washing liquid (the filtrate was incorporated into the washing liquid). The manganese dioxide was dried at 120 ° C for 24 h, and then a slurry was prepared with a mass ratio of manganese dioxide, conductive carbon and PVDF of 7:2:1, coated on titanium foil, and fully dried in a vacuum oven at 80 ° C for 12 h to prepare a positive electrode sheet;

[0052] The concentration of Mn ions in the washing solution was tested by ICP, and then an aqueous zinc ion battery electrolyte was prepared according to a molar ratio of manganese sulfate to zinc sulfate of 0.1:2. The obtained positive electrode sheet, aqueous zinc ion battery electrolyte and zinc foil were made into button batteries.

[0053] Example 4

[0054] 2 g of retired lithium manganese oxide positive electrode material was mixed with 10 mL of 0.5 mol / L sulfuric acid solution, stirred at 800 rpm for 2 h, and then transferred to a reactor for hydrothermal reaction at 180 ° C for 20 h. After the reaction was completed, the obtained black precipitated manganese dioxide was filtered and washed with deionized water to obtain manganese dioxide and washing liquid (the filtrate was incorporated into the washing liquid). The manganese dioxide was dried at 120 ° C for 24 h, and then a slurry was prepared with a mass ratio of manganese dioxide, conductive carbon and PVDF of 7:2:1, coated on titanium foil, and fully dried in a vacuum oven at 80 ° C for 12 h to prepare a positive electrode sheet;

[0055] The concentration of Mn ions in the washing solution was tested by ICP, and then an aqueous zinc ion battery electrolyte was prepared according to a molar ratio of manganese sulfate to zinc sulfate of 0.1:2. The obtained positive electrode sheet, aqueous zinc ion battery electrolyte and zinc foil were made into button batteries.

[0056] It can be seen from the above embodiments that the present invention provides a method for recycling retired lithium-ion batteries to prepare aqueous zinc-ion batteries and an aqueous zinc-ion battery. Figure 2 The XRD pattern of manganese dioxide obtained in Example 1 is shown in FIG. Figure 2 It can be seen that the obtained manganese dioxide has no secondary phase and impurity peaks, and all diffraction peaks point to the manganese dioxide standard card (PDF#72-1984), which is a standard manganese dioxide material; Figure 3 This is a SEM image of the manganese dioxide obtained in Example 1. As can be seen from the figure, the manganese dioxide has a nanorod-like structure; Figure 3 The electrochemical performance diagram of the aqueous zinc-ion battery obtained in Example 1 shows that the regenerated aqueous zinc-ion battery has excellent specific capacity and cycle retention. This demonstrates that the present invention addresses the technical issues of complex processes, high energy consumption, low utilization rates of waste gas and waste liquid generated, and low lithium-ion battery safety in the recycling of retired lithium-ion battery cathode materials, thus achieving significant results.

[0057] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for recycling retired lithium-ion batteries to prepare aqueous zinc-ion batteries, characterized in that: The following steps are involved: Step 1) mixing the retired lithium manganese oxide positive electrode material and the sulfuric acid solution and performing a hydrothermal reaction to obtain manganese dioxide and a washing solution; Step 2), measuring the manganese content in the washing liquid, and mixing the washing liquid with zinc sulfate to obtain an aqueous electrolyte; Step 3) Mix manganese dioxide, conductive carbon and polyvinylidene fluoride and apply the mixture on a foil, dry it to obtain a positive electrode sheet, and combine the positive electrode sheet, aqueous electrolyte and zinc foil to obtain an aqueous zinc ion battery.

2. The method for recycling retired lithium-ion batteries to prepare aqueous zinc-ion batteries according to claim 1, characterized in that: In step 1), the mass volume ratio of the retired lithium manganese oxide positive electrode material and the sulfuric acid solution is 2.0-3.0 g: 0.5-1 mol / L.

3. The method for recycling retired lithium-ion batteries to prepare aqueous zinc-ion batteries according to claim 1 or 2, characterized in that: In step 1), the mixing is carried out under stirring conditions, the stirring speed is 700-1000 rpm, and the stirring time is 1-3 hours.

4. The method for recycling retired lithium-ion batteries to prepare aqueous zinc-ion batteries according to claim 3, characterized in that: In step 1), the temperature of the hydrothermal reaction is 140 to 220° C., and the time of the hydrothermal reaction is 16 to 32 hours.

5. The method for recycling retired lithium-ion batteries to prepare aqueous zinc-ion batteries according to claim 1, 2 or 4, wherein: In step 2), the molar ratio of manganese ions to zinc ions in the aqueous electrolyte is 0.1:1-2.

6. The method for recycling retired lithium-ion batteries to prepare aqueous zinc-ion batteries according to claim 5, characterized in that: In step 3), the mass ratio of manganese dioxide, conductive carbon and polyvinylidene fluoride is 6-10:1-3:1-2.

7. The method for recycling retired lithium-ion batteries to prepare aqueous zinc-ion batteries according to claim 1 or 6, characterized in that: In step 3), the foil comprises titanium foil.

8. The method for recycling retired lithium-ion batteries to prepare aqueous zinc-ion batteries according to claim 7, characterized in that: In step 3), the drying temperature is 70-100° C., and the drying time is 10-15 hours.

9. An aqueous zinc ion battery prepared by the method according to any one of claims 1 to 8.

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