WO2024036700A1 - Sodium-ion battery prussian sodium positive electrode material recovery method and use thereof - Google Patents

Abstract

Provided in the present invention are a sodium-ion battery Prussian sodium positive electrode material recovery method and the use thereof. The recovery method comprises the following steps: (1) disassembling a decommissioned and/or waste Prussian sodium-ion battery, separating out a Prussian positive electrode plate, washing the obtained Prussian positive electrode plate with water, and filtering same to obtain a positive electrode carrier plate and a mixed solution; and (2) mixing the mixed solution obtained in step (1) with an alkali liquor, and filtering same to obtain a ferrocyanide solution and a transition metal precipitate. The recovery process flow of the present invention is ingenious, the operation is simple, the raw materials are cheap, the solvent used is an alkaline solution, the method is environmentally friendly and pollution-free, and the obtained product is easy to purify and separate, such that industrial large-scale production can be realized.

Description

A recycling method and application of Prussian sodium cathode material for sodium ion battery Technical field

The invention belongs to the technical field of sodium-ion battery recycling and relates to a method for recycling Prussian sodium positive electrode materials of sodium-ion batteries and its application.

Background technique

In recent years, as lithium-ion batteries have been running at high speed on the track of the new energy industry and have been widely used in electric vehicles, portable electronic devices and smart daily necessities, the already rare lithium resources have become even more scarce. At the same time, problems such as the shortage of lithium resources and rising prices have seriously hindered social development. However, Na elements of the same main group are more abundant in the earth's crust, and their distribution range is relatively wide, and the physical and chemical properties of the two are similar. Therefore, sodium-ion batteries are expected to replace lithium-ion batteries and become energy storage devices in the future.

Prussian derivative materials are currently one of the most promising cathode materials for sodium-ion batteries. It has the characteristics of an open nanoframe structure, large space gaps and ion channels, high specific surface area and controllable functionalization, which is conducive to the rapid insertion and extraction of sodium ions, and has been widely favored and studied. However, Prussian derivative materials have shortcomings that are difficult to produce due to their structural properties: The first is that the Prussian-like structure contains a large amount of ferrocyanide ions and cyanide ions, resulting in low toxicity of the material itself and a large amount of waste. Prussian sodium-like cathode materials will have a huge impact on environmental pollution and human activities. The second is that China has high standards and strict requirements for the treatment and discharge of cyanide-containing substances, which has caused certain difficulties in production and mass production. This has become a thorny problem for the use of Prussia and its derivatives in cathode materials.

In order to solve the above problems, retired or discarded Prussian derivative sodium cathode materials can only be recycled.

CN114229875A discloses a comprehensive recycling method for waste sodium ion batteries, which includes mixing and grinding battery black powder with a pre-leaching agent, then adding reducing agent and ammonia liquid for leaching, solid-liquid separation to obtain leachate and solid, adding acid to the solid to dissolve the solid-liquid Separate to obtain carbon residue and filtrate, add alkali to the filtrate to adjust the pH, separate to obtain aluminum hydroxide, continue to add alkali to the filtrate to adjust the pH, separate to obtain manganese hydroxide, add the first oxidant, chelating agent and alkali to the leachate, and proceed Ammonia is evaporated, and solid-liquid separation is performed to obtain cobalt-containing insoluble matter and nickel-containing chelate solution.

The above scheme is aimed at conventional sodium-ion batteries. There are currently few studies on the recycling of Prussian sodium cathode materials. Therefore, there is an urgent need to develop a recycling method that can solve the pollution and resource recycling problems of Prussian sodium cathode materials.

Contents of the invention

The object of the present invention is to provide a method for recycling Prussian sodium cathode materials of sodium ion batteries and its application. The recycling process of the present invention is ingenious, simple to operate, and the raw materials are cheap. The solvent used is an alkaline solution, which is environmentally friendly and pollution-free, and The obtained product is easy to purify and separate, and can realize industrial large-scale production.

In order to achieve the purpose of this invention, the present invention adopts the following technical solutions:

In a first aspect, the invention provides a method for recycling Prussian sodium cathode materials for sodium ion batteries. The recycling method includes the following steps:

(1) Disassemble retired and/or used Prussian-type sodium-ion batteries, separate the Prussian-type positive electrode pieces, wash the obtained Prussian-type positive electrode pieces, and filter to obtain the positive electrode carrier pieces and mixed liquid;

(2) Mix the mixed solution obtained in step (1) with an alkali solution, and filter to obtain a ferrocyanide solution and a transition metal precipitate.

The present invention recycles decommissioned or discarded Prussian-type positive electrode material resources of sodium-ion batteries. By washing the Prussian-type materials in the positive electrode sheets and soaking them in alkaline solution, the Prussian-type positive electrode materials are dissolved in the alkaline solution, and then the Prussian-type positive electrode materials are dissolved in the alkaline solution. The process prepares sodium ferrocyanide or potassium ferrocyanide and corresponding transition metal precipitates, realizing the recovery of sodium cathode material resources. This method avoids the loss of Prussian cathode material resources, and this recycling method technology Simple, no pollution to the environment, and obvious economic benefits.

Preferably, the Prussian sodium-ion battery in step (1) includes any one or a combination of at least two of button batteries, soft pack batteries, cylindrical batteries or prismatic batteries.

Preferably, the cathode material of the Prussian-based sodium ion battery in step (1) includes manganese-based Prussian derivatives, iron-based Prussian-based derivatives, nickel-based Prussian-based derivatives, cobalt-based Prussian-based derivatives, and copper-based Prussian-based derivatives. Any one or a combination of at least two of the derivatives or zinc-based Prussian derivatives.

Preferably, the temperature of the water washing treatment in step (1) is 25-90°C, for example: 25°C, 30°C, 50°C, 60°C or 90°C, etc.

Preferably, the time of the water washing treatment in step (1) is 2 to 120h, for example: 2h, 10h, 20h, 60h or 120h, etc.

Preferably, an inert gas is introduced during the water washing process in step (1).

Preferably, the alkali solution in step (2) includes sodium hydroxide solution and/or potassium hydroxide solution.

Preferably, the molar ratio of the solute in the alkali solution and the Prussian cathode material in the mixed solution in step (2) is (2-4):1, for example: 2:1, 2.5:1, 3:1, 3.5:1 Or 4:1 etc.

Preferably, the mixing temperature in step (2) is 25-90°C, for example: 25°C, 30°C, 50°C, 60°C or 90°C, etc.

Preferably, the mixing time in step (2) is 2 to 120h, for example: 2h, 10h, 20h, 60h or 120h.

Preferably, the solute of the ferrocyanide solution in step (2) includes sodium ferrocyanide or potassium ferrocyanide.

In a second aspect, the present invention provides an application of the recycling method as described in the first aspect, wherein the ferrocyanide solution prepared by the recycling method is used to synthesize Prussian sodium cathode materials.

Compared with the existing technology, the present invention has the following beneficial effects:

(1) The recycling process of the present invention is ingenious, simple to operate, and the raw materials are cheap. The solvent used is an alkaline solution, which is environmentally friendly and pollution-free. The obtained product is easy to purify and separate, and can realize industrial large-scale production.

(2) The present invention recycles Prussian-type cathode materials, reduces the discharge of cyanide-containing wastewater, reduces industrial costs, and avoids environmental pollution.

Description of drawings

Figure 1 is a process flow chart of the Prussian sodium cathode material recovery method for sodium ion batteries described in Example 1.

Figure 2 is an SEM image of the Prussian white material prepared by the recycling method described in Example 1.

Figure 3 is an SEM image of Mn ₃ O ₄ produced by the recovery method described in Example 1.

Figure 4 is an SEM image of the filter obtained by the recovery method described in Example 7.

Figure 5 is an XRD pattern of the Prussian white material prepared by the recycling method described in Example 1.

Figure 6 is an XRD pattern of Mn ₃ O ₄ prepared by the recovery method described in Example 1.

Detailed ways

The technical solution of the present invention will be further described below through specific implementations. Those skilled in the art should understand that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

Example 1

This embodiment provides a method for recycling Prussian sodium cathode materials for sodium ion batteries. The process flow chart of the recycling method is shown in Figure 1. The recycling method includes the following steps:

(1) Disassemble the Prussian sodium-ion battery cells after complete discharge treatment, pick out the positive and negative electrode sheets and separators respectively, and remove the positive electrode containing manganese-based Prussian white (Na ₂ MnFe(CN) ₆ ) positive electrode material. The sheet is dissolved in deionized water and washed with water. After the positive electrode sheet is fully stirred and dissolved, the aluminum foil metal carrier sheet is filtered and extracted, leaving a quantitative manganese-based Prussian white suspension. The aluminum foil is sold to metal processing plants and recycled again;

(2) Add the filtered manganese-based Prussian white (Na ₂ MnFe(CN) ₆ ) suspension into a specific reaction kettle, add a certain amount of sodium hydroxide (NaOH), and its Prussian white (Na ₂ MnFe(CN) ₆ ) The molar ratio to sodium hydroxide is 1:3. Then stir vigorously, heat to 50°C and fully mix the reaction for 24 hours. Nitrogen protective gas is introduced throughout the process. The solution after the reaction is filtered to obtain sodium ferrocyanide (Na ₄ Fe(CN) ₆ ) solution and Manganese hydroxide (Mn(OH) ₂ ) precipitates the filter residue, and removes the filter residue to obtain sodium ferrocyanide solution;

The obtained sodium ferrocyanide (Na ₄ Fe(CN) ₆ ) solution can continue to be used to synthesize Prussian sodium cathode materials. The manganese hydroxide (Mn(OH) ₂ ) precipitate is recovered and dried in the air to remove the water to obtain the corresponding manganese tetraoxide (Mn ₃ O ₄ ), which can be used for the synthesis of ternary cathode materials and can also be used for Prussian type The synthesis of cathode materials provides sources of raw materials.

The SEM image of the Prussian white material is shown in Figure 2, and the XRD pattern of the Prussian white material is shown in Figure 5.

The SEM picture of Mn ₃ O ₄ is shown in Figure 3, and the XRD pattern of Mn ₃ O ₄ is shown in Figure 6.

The chemical equation of the recovery method is: Na ₂ MnFe(CN) ₆ +2NaOH+O ₂ →Na ₄ Fe(CN) ₆ +Mn ₃ O ₄ ↓.

Example 2

This embodiment provides a method for recycling Prussian sodium cathode materials for sodium ion batteries. The recycling method includes the following steps:

(1) Disassemble the Prussian sodium-ion battery cells after complete discharge treatment, pick out the positive and negative electrode sheets and separators respectively, and remove the iron-based Prussian white (Na ₂ Fe[Fe(CN) ₆ ]) positive electrode. The positive electrode sheet of the material is dissolved in deionized water and washed with water. After the positive electrode sheet is fully stirred and dissolved, the aluminum foil metal carrier sheet is filtered and extracted, leaving a quantitative iron-based Prussian white suspension. The aluminum foil is sold to metal processing plants and recycled again;

(2) Add the filtered iron-based Prussian white (Na ₂ Fe [Fe(CN) ₆ ]) suspension into a specific reaction kettle, add a certain amount of sodium hydroxide (NaOH), and add the iron-based Prussian white (Na ₂ Fe The molar ratio of [Fe(CN) ₆ ]) to sodium hydroxide is 1:2. Then stir vigorously, and mix the two thoroughly for 12 hours at room temperature. Nitrogen protective gas is passed through the whole process. The solution after the reaction is filtered to obtain sodium ferrocyanide (Na ₄ Fe(CN) ₆ ) solution. Precipitate the filter residue with iron hydroxide (Fe(OH) ₃ ), and remove the filter residue to obtain sodium ferrocyanide solution.

The obtained sodium ferrocyanide (Na ₄ Fe(CN) ₆ ) solution can continue to be used to synthesize Prussian sodium cathode materials. The recovered iron hydroxide (Fe(OH) ₃ ) precipitate can be used for the synthesis of ternary cathode materials, and can also be used to provide a raw material source for the synthesis of Prussian cathode materials.

The chemical equation of the recovery method is: Na ₂ Fe[Fe(CN) ₆ ]+3NaOH→Na ₄ Fe(CN) ₆ +Fe(OH) ₃ ↓.

Example 3

This embodiment provides a method for recycling Prussian sodium cathode materials for sodium ion batteries. The recycling method includes the following steps:

(1) Disassemble the Prussian sodium-ion battery cells after complete discharge treatment, pick out the positive and negative electrode sheets and separators respectively, and remove the positive electrode containing cobalt-based Prussian white (Na ₂ CoFe (CN) ₆ ) positive electrode material. The sheet is dissolved in deionized water and washed with water. After the positive electrode sheet is fully stirred and dissolved, the aluminum foil metal carrier sheet is filtered and extracted, leaving a quantitative cobalt-based Prussian white suspension. The aluminum foil is sold to metal processing plants and recycled again;

(2) Add the filtered cobalt-based Prussian white (Na ₂ CoFe(CN) ₆ ) suspension into a specific reaction kettle, add a certain amount of sodium hydroxide (NaOH), and the cobalt-based Prussian white (Na ₂ CoFe(CN) ₆ ) The molar ratio to sodium hydroxide is 1:2. Then stir vigorously, and mix the two thoroughly for 12 hours at room temperature. Nitrogen protective gas is passed through the whole process. The solution after the reaction is filtered to obtain sodium ferrocyanide (Na ₄ Fe(CN) ₆ ) solution. Precipitate the filter residue with cobalt hydroxide (Co(OH) ₂ ), and remove the filter residue to obtain sodium ferrocyanide solution.

The obtained sodium ferrocyanide (Na ₄ Fe(CN) ₆ ) solution can continue to be used to synthesize Prussian sodium cathode materials. The recovered cobalt hydroxide (Co(OH) ₂ ) precipitate can be used for the synthesis of ternary cathode materials or cobalt carbonate, and can also be used to provide a raw material source for the synthesis of Prussian cathode materials.

The chemical equation of the recovery method is: Na ₂ Co[Fe(CN) ₆ ]+2NaOH→Na ₄ Fe(CN) ₆ +Co(OH) ₂ ↓.

Example 4

This embodiment provides a method for recycling Prussian sodium cathode materials for sodium ion batteries. The recycling method includes the following steps:

(1) Disassemble the Prussian sodium-ion battery cells after complete discharge treatment, pick out the positive and negative electrode sheets and separators respectively, and remove the positive electrode containing nickel-based Prussian blue (Na ₂ NiFe(CN) ₆ ) positive electrode material. The sheet is dissolved in deionized water and washed with water. After the positive electrode sheet is fully stirred and dissolved, the aluminum foil metal carrier sheet is filtered and extracted, leaving a quantitative nickel-based Prussian blue suspension. The aluminum foil is sold to metal processing plants and recycled again;

(2) Add the filtered nickel-based Prussian blue (Na ₂ NiFe(CN) ₆ ) suspension into a specific reaction kettle, add a certain amount of sodium hydroxide (NaOH), and the nickel-based Prussian blue (Na ₂ NiFe(CN) ₆ ) The molar ratio to sodium hydroxide is 1:3. Then stir vigorously, and mix the two thoroughly for 12 hours at room temperature. Nitrogen protective gas is passed through the whole process. The solution after the reaction is filtered to obtain sodium ferrocyanide (Na ₄ Fe(CN) ₆ ) solution. Precipitate the filter residue with nickel hydroxide (Ni(OH) ₂ ), and remove the filter residue to obtain sodium ferrocyanide solution.

The obtained sodium ferrocyanide (Na ₄ Fe(CN) ₆ ) solution can continue to be used to synthesize Prussian sodium cathode materials. The recovered nickel hydroxide (Ni(OH) ₂ ) precipitate can be used for the synthesis of ternary cathode materials or cobalt carbonate, and can also be used to provide a raw material source for the synthesis of Prussian cathode materials.

The chemical equation of the recovery method is: Na ₂ Ni[Fe(CN) ₆ ]+2NaOH→Na ₄ Fe(CN) ₆ +Ni(OH) ₂ ↓.

Example 5

This embodiment provides a method for recycling Prussian sodium cathode materials for sodium ion batteries. The recycling method includes the following steps:

(1) Disassemble the Prussian sodium-ion battery cells after complete discharge treatment, pick out the positive and negative electrode sheets and separators respectively, and remove the positive electrode containing copper-based Prussian blue (Na ₂ CuFe(CN) ₆ ) positive electrode material. The sheet is dissolved in deionized water and washed with water. After the positive electrode sheet is fully stirred and dissolved, the aluminum foil metal carrier sheet is filtered and extracted, leaving a quantitative copper-based Prussian blue suspension. The aluminum foil is sold to metal processing plants and recycled again;

(2) Add the filtered copper-based Prussian blue (Na ₂ CuFe(CN) ₆ ) suspension into a specific reaction kettle, add a certain amount of sodium hydroxide (NaOH), and add the copper-based Prussian blue (Na ₂ CuFe(CN) ₆ ) The molar ratio to sodium hydroxide is 1:3. Then stir vigorously, mix the two thoroughly at room temperature, and react for 12 hours. Nitrogen protective gas is introduced throughout the process. The solution after the reaction is filtered to obtain sodium ferrocyanide (Na ₄ Fe(CN) ₆ ) solution. Precipitate the filter residue with copper hydroxide (Cu(OH) ₂ ), and remove the filter residue to obtain sodium ferrocyanide solution.

The obtained sodium ferrocyanide (Na ₄ Fe(CN) ₆ ) solution can continue to be used to synthesize Prussian sodium cathode materials. The recovered copper hydroxide (Cu(OH) ₂ ) precipitate can be used for the doping synthesis of ternary cathode materials or cobalt carbonate, and can also be used to provide a raw material source for the synthesis of Prussian cathode materials.

The chemical equation of the recovery method is: Na ₂ Cu[Fe(CN) ₆ ]+2NaOH→Na ₄ Fe(CN) ₆ + Cu(OH) ₂ ↓.

Example 6

This embodiment provides a method for recycling Prussian sodium cathode materials for sodium ion batteries. The recycling method includes the following steps:

(1) Disassemble the Prussian sodium-ion battery cells after complete discharge treatment, pick out the positive and negative electrode sheets and separators respectively, and remove the positive electrode containing zinc-based Prussian blue (Na ₂ ZnFe(CN) ₆ ) positive electrode material. The sheet is dissolved in deionized water and washed with water. After the positive electrode sheet is fully stirred and dissolved, the aluminum foil metal carrier sheet is filtered and extracted, leaving a quantitative zinc-based Prussian blue suspension. The aluminum foil is sold to metal processing plants and recycled again;

(2) Add the filtered zinc-based Prussian blue (Na ₂ ZnFe(CN) ₆ ) suspension into a specific reaction kettle, add a certain amount of sodium hydroxide (NaOH), and add the zinc-based Prussian blue (Na ₂ ZnFe(CN) ₆ ) The molar ratio to sodium hydroxide is 1:3. Then stir vigorously, and mix the two thoroughly for 12 hours at room temperature. Nitrogen protective gas is passed through the whole process. The solution after the reaction is filtered to obtain sodium ferrocyanide (Na ₄ Fe(CN) ₆ ) solution. Precipitate the filter residue with zinc hydroxide (Zn(OH) ₂ ), and remove the filter residue to obtain sodium ferrocyanide solution.

The obtained sodium ferrocyanide (Na ₄ Fe(CN) ₆ ) solution can continue to be used to synthesize Prussian sodium cathode materials. The recovered zinc hydroxide (Zn(OH) ₂ ) precipitate can be used for the doping synthesis of ternary cathode materials or cobalt carbonate, and can also be used to provide a raw material source for the synthesis of Prussian cathode materials.

The chemical equation of the recovery method is: Na ₂ Cu[Fe(CN) ₆ ]+2NaOH→Na ₄ Fe(CN) ₆ +Zn(OH) ₂ ↓.

Example 7

The only difference between this example and Example 1 is that the molar ratio of Prussian white (Na ₂ MnFe(CN) ₆ ) to sodium hydroxide is 1:1. Other conditions and parameters are exactly the same as Example 1. SEM of the system after the reaction The diagram is shown in Figure 4. It can be seen from Figure 4 that if the amount of alkali solution is too small, the positive electrode material cannot react completely, which in turn leads to a significant decrease in the recovery efficiency of the material.

Example 8

The only difference between this embodiment and Example 1 is that the molar ratio of Prussian white (Na ₂ MnFe(CN) ₆ ) to sodium hydroxide is 1:5, and other conditions and parameters are exactly the same as those in Example 1.

It can be seen from the comparison between Example 1 and Examples 7-8 that in the recovery method of the present invention, the molar ratio of the Prussian cathode material and the alkali will affect the recovery effect. If the amount of alkali solution added is too large, the alkali solution will overflow. It is wasteful. The obtained sodium ferrocyanide or potassium ferrocyanide solution contains a large amount of sodium ions or potassium ions, which increases the subsequent processing of sodium ions or potassium ions; if the amount of alkali added is too small, As a result, the reaction is insufficient, the final product is impure, and the Prussian material with a changed structure and the corresponding metal oxidation or hydroxide mixture are obtained, resulting in complicated separation and purification and increased costs.

From the comparison between Example 1 and Comparative Example 1, it can be seen that the present invention recycles retired or discarded Prussian-type positive electrode material resources of sodium-ion batteries, and makes Prussian-type materials in the positive electrode sheets by rinsing and soaking them in alkaline solutions. The cathode material is dissolved in an alkaline solution, and then subjected to subsequent processing to prepare sodium ferrocyanide or potassium ferrocyanide and the corresponding transition metal precipitate, realizing the recovery of sodium cathode material resources. This method avoids the Prussian-type There is no loss of cathode material resources, and this recycling method has a simple process, no pollution to the environment, and obvious economic benefits.

The applicant declares that the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the technical field should understand that any person skilled in the technical field will not use the invention disclosed in the present invention. Within the technical scope, easily conceivable changes, combinations or substitutions fall within the protection scope and disclosure scope of the present invention.

Claims (10)

A method for recycling Prussian sodium cathode materials for sodium ion batteries, characterized in that the recycling method includes the following steps: (1) Disassemble retired and/or used Prussian-type sodium-ion batteries, separate the Prussian-type positive electrode pieces, wash the obtained Prussian-type positive electrode pieces, and filter to obtain the positive electrode carrier pieces and mixed liquid; (2) Mix the mixed solution obtained in step (1) with an alkali solution, and filter to obtain a ferrocyanide solution and a transition metal precipitate. The recycling method according to claim 1, wherein the Prussian sodium-ion battery in step (1) includes any one or at least two of button batteries, soft pack batteries, cylindrical batteries or prismatic batteries. combination. The recycling method according to claim 1 or 2, characterized in that the positive electrode material of the Prussian-based sodium ion battery in step (1) includes manganese-based Prussian-based derivatives, iron-based Prussian-based derivatives, and nickel-based Prussian-based derivatives. Any one or a combination of at least two of the following: cobalt-based Prussian derivatives, copper-based Prussian derivatives or zinc-based Prussian derivatives. The recovery method according to any one of claims 1 to 3, characterized in that the temperature of the water washing treatment in step (1) is 25-90°C; Preferably, the time of the water washing treatment in step (1) is 2 to 120 hours. The recovery method according to any one of claims 1 to 4, characterized in that inert gas is introduced during the water washing process in step (1). The recovery method according to any one of claims 1 to 5, characterized in that the alkali solution in step (2) includes sodium hydroxide solution and/or potassium hydroxide solution. The recovery method according to any one of claims 1 to 6, characterized in that the molar ratio of the solute in the alkali solution and the Prussian cathode material in the mixed solution in step (2) is (2-4):1. The recovery method according to any one of claims 1 to 7, characterized in that the mixing temperature in step (2) is 25-90°C; Preferably, the mixing time in step (2) is 2 to 120 hours. The recovery method according to any one of claims 1 to 8, characterized in that the solute of the ferrocyanide solution in step (2) includes sodium ferrocyanide or potassium ferrocyanide. An application of the recovery method according to any one of claims 1 to 9, characterized in that the ferrocyanide solution prepared by the recovery method is used to synthesize Prussian sodium cathode materials.

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