A method for efficiently recycling waste zinc-manganese dry batteries to prepare positive electrode materials for aqueous batteries

Abstract

The present invention relates to a method for efficiently recycling waste zinc-manganese dry batteries to prepare positive electrode materials for aqueous batteries. The waste zinc-manganese dry batteries are first mechanically disassembled, and the positive and negative electrode waste materials are separated and pulverized separately. A certain amount of solid alkali is weighed and mixed with a dispersant, and stirred uniformly to obtain a composite alkaline solution. The pulverized positive and negative electrode waste materials are mixed in a predetermined proportion, soaked in the composite alkaline solution, and reacted at room temperature for a period of time to obtain a slurry. The resulting slurry is filtered or centrifuged to separate the powder and filtrate (supernatant), and the filtrate (supernatant) is recovered for repeated use. The separated powder is first washed several times with a dilute acid solution, then washed with water and ethanol, and finally dried to obtain a material for aqueous battery positive electrodes. This invention reports for the first time a method for simply and efficiently producing carbon-containing aqueous battery positive electrode materials by mixing the positive and negative electrode waste materials from waste zinc-manganese dry batteries in a predetermined proportion and treating them with a room-temperature alkaline solution. This method not only effectively addresses the environmental pollution and high energy consumption associated with waste dry battery recycling, but also provides a new approach for preparing composite manganese-based aqueous battery positive electrodes.

Description

Technical Field

[0001] The present invention relates to an efficient zinc-manganese dry cell recycling method, and in particular to a method for preparing aqueous battery positive electrode materials based on the efficient recycling of waste dry cells. Background Art

[0002] The electrode materials in used dry-cell batteries are primarily composed of mixed zinc-manganese oxide, alkaline potassium hydroxide, carbon, and a binder. Currently, there are two main types of technologies for recycling used zinc-manganese dry-cell batteries: one is the wet method, which involves acid dissolution of the electrode material, followed by pH adjustment and chemical or electrodeposition to further recover key elements such as manganese. For example, CN112259754.B discloses a method for pressure leaching the positive electrode active material using an acid and oxidant system, resulting in a manganese-containing leachate with a 98.9% yield; CN107180977.B discloses a method for obtaining ZnS from an acidic solution and then electrolytically recovering MnO2. Another type is the pyrometallurgical method, which involves removing organic binders and conductive carbon from electrode materials through high-temperature incineration while simultaneously oxidizing the metals and their compounds. Low-boiling-point metals and their compounds are recovered as condensates, and the metals in the slag are further recovered through screening, pyrolysis, magnetic separation, or chemical methods. CN100480184.C discloses a method for recovering NH4Cl, Zn (ZnO), and MnSO4 chemicals from alkaline zinc-manganese dry batteries through crushing, dry distillation, dissolution, and purification. Existing recycling processes for spent dry battery electrode materials all involve strong acid (base) dissolution, subsequent precipitation and separation, or high-temperature incineration or electrolysis, ultimately yielding manganese-containing compounds such as MnSO4 (CN202011140468.2), MnO2 (CN201610445907.8), and LiMn2O4 (CN103746127B). In recent years, there are a few patent reports that the electrode waste of used batteries is recycled and directly used in the field of electrochemistry. For example, CN202010006813.7 separately recycles the positive electrode waste, cleans it, and then calcines it with Na + Obtain Na 0.44 MnO2 is used in sodium-ion batteries; CN201811111468.2 recycles cathode waste from batteries to produce a carbon package containing a mixture of ZnMn2O4 and carbon for use in sodium-ion supercapacitors. Furthermore, the electrode material ZnMn2O4 is mostly synthesized using aqueous solutions of manganese and zinc salts. For example, CN202011582949.9 uses ammonia solution to adjust the pH to form a precipitate followed by calcination. There are few reports on the solid-phase-solid-phase conversion synthesis of ZnMn2O4.

[0003] In summary, there is no patent or literature report on the direct use of waste dry cell positive and negative electrode wastes through a simple room temperature liquid phase treatment to obtain a controllable proportion of Zn xMn2O4-MnOOH-C composite materials can be directly used as positive electrode materials for aqueous batteries. Addressing the shortcomings of existing technologies, this invention reports for the first time a method for treating the positive and negative electrode waste from used zinc-manganese dry batteries with alkaline solution at room temperature, allowing for the controlled and efficient recovery of Zn, Mn, and C from the positive and negative electrodes. The recovered materials can then be directly used as positive electrode materials for aqueous batteries. Summary of the Invention

[0004] The technical problem solved by the present invention is to use composite alkali solution as the main body to achieve the common controllable high-efficiency and low-consumption recycling of positive and negative electrode waste materials of waste dry batteries, and directly prepare aqueous battery positive electrode materials with the recycled materials.

[0005] The present invention solves the technical problem by using a composite alkaline solution to recover materials from waste zinc-manganese dry cell electrode waste. The recovered materials can be directly used as positive electrode materials for aqueous batteries, including aqueous zinc ion systems, aqueous sodium ion systems, and aqueous magnesium ion systems.

[0006] The method for efficiently recycling waste zinc-manganese dry batteries to prepare positive electrode materials for aqueous batteries comprises the following steps:

[0007] Step 1: Mechanically disassemble the used zinc-manganese dry batteries, separate the positive and negative electrode wastes and crush them separately;

[0008] Step 2: Weigh the solid alkali and dispersant in a certain solid-liquid ratio, mix and stir evenly to obtain a composite alkali solution;

[0009] Step 3: Mix the crushed positive and negative electrode waste materials in a certain proportion, soak them in a composite alkali solution at a certain solid-liquid ratio, and stir them at room temperature for a period of time to obtain a slurry;

[0010] Step 4: The slurry obtained in step 3 is filtered or centrifuged to separate the filtrate (supernatant) and the powder. The filtrate (supernatant) is recovered for repeated use, and the separated powder is used for subsequent operations;

[0011] Step 5: Wash the powder obtained in step 4 with dilute acid detergent 1 to 5 times;

[0012] Step 6: Wash the powder obtained in step 5 with water and ethanol several times, and then dry it to recover the aqueous battery positive electrode material;

[0013] In step 2, the solid base is one or more of NaOH, KOH and Ca(OH)2;

[0014] The dispersant comprises one or more of water, ethanol, glycerol, N,N-dimethylformamide (DFM) and dimethyl sulfoxide (DMSO);

[0015] The solid base and the dispersant are mixed at a solid-liquid ratio of (0.1-10) g: (10-10000) mL.

[0016] Furthermore, in step 1, the electrode waste powder is screened through a 10-200 mesh sieve.

[0017] Furthermore: in step 3, the ratio of positive and negative electrode waste is between (1-20) g: (0-20) g.

[0018] Furthermore: in step 3, the solid-liquid ratio of the mixed positive and negative electrode waste and the composite alkali solution is (0.1-10) g: (10-100) mL.

[0019] Furthermore: in step 3, the room temperature ranges from 0 to 40° C., and the stirring time is from 10 min to 48 h.

[0020] Furthermore: in step 5, the dilute acid washing solution is an aqueous solution of one or more of hydrochloric acid, sulfuric acid, nitric acid, acetic acid and oxalic acid, and the acid concentration range of the dilute acid washing solution is 0.0001 to 0.01 mol / L.

[0021] Furthermore: in step 6, the drying temperature is 60-80°C, the drying environment is vacuum, and the drying time is 8-15 hours.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The positive and negative electrode waste materials in the waste dry batteries are fully utilized as zinc, manganese and carbon sources, and a controllable proportion of Zn is recovered through simple post-processing. x The Mn2O4-MnOOH-C material can be directly used as the positive electrode material for aqueous batteries. This invention uses waste dry cell batteries as raw materials, achieving controllable and complete recycling of the positive and negative electrode waste within the waste batteries. It is expected to provide a new material preparation method for composite manganese-based aqueous battery positive electrodes while being environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is an SEM image of the positive electrode powder of the waste zinc-manganese dry battery in Example 1 of the present invention.

[0025] Figure 2 This is a pH value diagram of the positive electrode powder of waste zinc-manganese dry battery waste in 3 mol / L ZnSO4 solution in Example 1 of the present invention.

[0026] Figure 3 This is a SEM image of the aqueous battery positive electrode material powder sample recovered in Example 1 of the present invention.

[0027] Figure 4This is the EDS-mapping diagram of the aqueous battery positive electrode material powder sample recovered in Example 1 of the present invention.

[0028] Figure 5 This is the XPS graph of the aqueous battery positive electrode material powder sample C1s recovered in Example 1 of the present invention.

[0029] Figure 6 This is the XPS graph of Mn 2p of the aqueous battery cathode material powder sample recovered in Example 1 of the present invention.

[0030] Figure 7 This is the XPS graph of Zn 2p of the aqueous battery cathode material powder sample recovered in Example 1 of the present invention.

[0031] Figure 8 This is the XRD pattern of the aqueous battery positive electrode material powder sample recovered in Example 1 of the present invention.

[0032] Figure 9 This is a pH value diagram of the aqueous battery positive electrode material powder sample recovered in Example 1 of the present invention in a 3 mol / L ZnSO4 solution.

[0033] Figure 10 The figure shows the cycle performance and coulombic efficiency curve of an aqueous zinc ion button battery prepared from the aqueous battery positive electrode material powder sample recovered in Example 1 of the present invention.

[0034] Figure 11 This is a charge and discharge curve diagram of an aqueous zinc ion button battery prepared from the aqueous battery positive electrode material powder sample recovered in Example 1 of the invention.

[0035] Figure 12 This is a CV curve diagram of an aqueous zinc ion button battery prepared from the aqueous battery positive electrode material powder sample recovered in Example 1 of the invention.

[0036] Figure 13 This is a SEM image of the aqueous battery positive electrode material powder sample recovered in Example 2 of the present invention.

[0037] Figure 14 This is the EDS-mapping diagram of the aqueous battery positive electrode material powder sample recovered in Example 2 of the present invention.

[0038] Figure 15 This is the XPS graph of the aqueous battery positive electrode material powder sample C1s recovered in Example 2 of the present invention.

[0039] Figure 16 This is the XPS graph of Mn 2p of the aqueous battery cathode material powder sample recovered in Example 2 of the present invention.

[0040] Figure 17 This is the XPS graph of Zn 2p of the aqueous battery cathode material powder sample recovered in Example 2 of the present invention.

[0041] Figure 18 This is the XRD pattern of the aqueous battery positive electrode material powder sample recovered in Example 2 of the present invention. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to the embodiments, specifically according to the following implementation method:

[0043] Example 1:

[0044] The present invention discloses a method for efficiently recycling waste zinc-manganese dry batteries to prepare positive electrode materials for aqueous batteries. The specific operation scheme is as follows: first, the waste zinc-manganese dry batteries are mechanically disassembled, the positive and negative electrode waste materials are separated, and they are crushed separately and passed through a 50-mesh sieve. 1g of KOH is weighed and dispersed in 250mL of water to obtain a composite alkali solution. 2g of the crushed positive electrode waste powder is dispersed in 100mL of the composite alkali solution, and the mixture is stirred continuously in a beaker at 25°C for 15 minutes to obtain a slurry. The slurry is filtered to obtain a filtrate and powder, and the filtrate is recovered for repeated use. The powder is washed twice with a 0.01mol / L hydrochloric acid solution, then washed three times with deionized water, and once with ethanol. The powder is collected and dried in a vacuum drying oven at 60°C for 12 hours to obtain aqueous battery positive electrode material powder. The powder was ground with the conductive agent acetylene black and the binder polyvinylidene fluoride (PVDF) in a mass ratio of 7:2:1 in N-methylpyrrolidone (NMP) solvent until the mixture was uniform, and then coated on a stainless steel foil. After drying at 80°C for 12 hours, it was cut into discs with a diameter of 12 mm as the positive electrode; then a round zinc sheet with a diameter of 16 mm was used as the negative electrode, 3 mol / L ZnSO4 was used as the electrolyte, and glass fiber was used as the separator. It was assembled in a 2032 type battery shell and sealed to obtain an aqueous zinc ion battery. Its constant current charge and discharge test voltage range is 1.0~1.8V, and the current density is 50mA / g; the CV test voltage range is 1.0~1.8V, and the scan rate is 0.1mV / s. The cycle performance, charge and discharge curve and CV of the aqueous zinc ion button battery prepared from the recycled material powder are as follows. Figure 10 、 Figure 11 and Figure 12 shown.

[0045] Example 2:

[0046] The present invention discloses a method for efficiently recycling waste zinc-manganese dry batteries to prepare positive electrode materials for aqueous batteries. The specific operation scheme is as follows: first, the waste zinc-manganese dry batteries are mechanically disassembled, the positive and negative electrode waste materials are separated and pulverized separately, and then passed through a 50-mesh sieve. 2.5g of KOH is weighed and dispersed in 250mL of water to obtain a composite alkali solution. 2g of the pulverized positive electrode and 1g of the negative electrode waste powder are dispersed in 100mL of the composite alkali solution, and the mixture is stirred continuously in a beaker at 25°C for 24 hours to obtain a slurry. The slurry is filtered to obtain a filtrate and powder, and the filtrate is recovered for repeated use. The powder is washed twice with a 0.01mol / L hydrochloric acid solution, then washed five times with deionized water and once with ethanol. The powder is collected and dried in a vacuum drying oven at 60°C for 12 hours to obtain a powder of aqueous battery positive electrode material.

[0047] Example 3:

[0048] The present invention discloses a method for efficiently recycling waste zinc-manganese dry batteries to prepare positive electrode materials for aqueous batteries. The specific operation scheme is as follows: First, the waste zinc-manganese dry batteries are mechanically disassembled, and the positive and negative electrode waste materials are separated and pulverized separately, and then passed through a 30-mesh sieve. 0.5g of KOH and 1g of NaOH are weighed and dispersed in a mixture of 225mL of water and 25mL of ethanol to obtain a composite alkaline solution. 2g of the pulverized positive electrode waste powder is dispersed in 100mL of the composite alkaline solution and stirred continuously in a beaker at 25°C for 1 hour to obtain a slurry. The slurry is filtered to obtain a filtrate and powder, and the filtrate is recovered for repeated use. The powder is washed twice with a 0.005mol / L acetic acid solution, then washed three times with deionized water and once with ethanol. The powder is collected and dried in a vacuum drying oven at 60°C for 12 hours to obtain aqueous battery positive electrode material powder.

[0049] Example 4:

[0050] The present invention discloses a method for efficiently recycling waste zinc-manganese dry batteries to prepare positive electrode materials for aqueous batteries. The specific operation scheme is as follows: First, the waste zinc-manganese dry batteries are mechanically disassembled, and the positive and negative electrode waste materials are separated and pulverized separately, and then passed through a 100-mesh sieve. 1g of KOH and 1g of NaOH are weighed and dispersed in a mixture of 150mL of water and 100mL of ethanol to obtain a composite alkaline solution. 1g of the pulverized positive electrode and 0.25g of the negative electrode waste powder are dispersed in 100mL of the composite alkaline solution, and the mixture is stirred continuously in a beaker at 25°C for 5 hours to obtain a slurry. The slurry is filtered to obtain a filtrate and powder, and the filtrate is recovered for repeated use. The powder is washed twice with a solution of 0.005mol / L sulfuric acid mixed with 0.005mol / L hydrochloric acid, then washed three times with deionized water and once with ethanol. The powder is collected and dried in a vacuum drying oven at 60°C for 12 hours to obtain aqueous battery positive electrode material powder.

Claims

1. A method for efficiently recycling waste zinc-manganese dry batteries to prepare positive electrode materials for aqueous batteries, characterized in that: The following steps are involved: Step 1: Mechanically disassemble the used zinc-manganese dry batteries, separate the positive and negative electrode wastes and crush them separately; Step 2: Weigh the solid alkali and dispersant in a certain solid-liquid ratio, mix and stir evenly to obtain a composite alkali solution; Step 3: Mix the crushed positive and negative electrode waste materials in a certain proportion, soak them in a composite alkali solution at a certain solid-liquid ratio, and stir them at room temperature for a period of time to obtain a slurry; Step 4: Filter or centrifuge the slurry obtained in step 3 to separate the filtrate and powder. The filtrate is recycled for repeated use, and the separated powder is used for subsequent operations; Step 5: Wash the powder obtained in step 4 with dilute acid detergent 1 to 5 times; Step 6: Wash the powder obtained in step 5 with water and ethanol several times, and then dry it to recover the aqueous battery positive electrode material; In step 2, the solid base is one or more of NaOH, KOH and Ca(OH)2; The dispersant comprises one or more of water, ethanol, glycerol, N,N-dimethylformamide (DFM) and dimethyl sulfoxide (DMSO); The solid base and the dispersant are mixed at a solid-liquid ratio of (0.1-10) g: (10-10000) mL.

2. The method according to claim 1, wherein: In the step 1, the electrode waste powder is screened through a 10-200 mesh sieve to obtain the electrode waste powder.

3. The method according to claim 1, wherein: In step 3, the mixing mass ratio of the positive and negative electrode wastes is (1-20) g:(0-20) g.

4. The method according to claim 1, wherein: In step 3, the solid-liquid ratio of the mixed positive and negative electrode waste and the composite alkali solution is (0.1-10) g: (10-100) mL.

5. The method according to claim 1, wherein: In step 3, the room temperature ranges from 0 to 40° C., and the stirring time is from 10 min to 48 h.

6. The method according to claim 1, wherein: In step 5, the dilute acid washing solution is an aqueous solution of one or more of hydrochloric acid, sulfuric acid, nitric acid, acetic acid and oxalic acid, and the acid concentration range of the dilute acid washing solution is 0.0001 to 0.01 mol / L.

7. The method according to claim 1, wherein: In step 6, the drying temperature is 60-80° C., the drying environment is vacuum, and the drying time is 8-15 hours.

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