Method for preparing manganese dioxide / iron oxide composite positive electrode material for aqueous zinc ion battery by using manganese ore tailing leaching solution

Abstract

The application discloses a method for preparing manganese sesquioxide / iron oxide (Mn2O3 / Fe2O3) composite positive electrode material for aqueous zinc ion batteries by using manganese ore tailing leaching solution. First, the manganese ore tailing leaching solution is obtained by taking manganese ore tailing as raw material, glucose as reducing agent and hydrochloric acid as leaching agent to perform reduction leaching reaction, and then the molar ratio of manganese ions to glucose in the leaching solution is properly adjusted, and finally the leaching solution is placed in a muffle furnace to perform heat treatment to obtain the Mn2O3 / Fe2O3 composite electrode material. The method has the advantages of simple operation, easy control of conditions, high product yield, low production cost, suitability for large-scale industrial production, and the prepared Mn2O3 / Fe2O3 composite positive electrode material has good zinc storage electrochemical performance.

Description

Technical Field

[0001] This invention relates to the field of aqueous battery electrode material preparation technology, specifically to a method for preparing a manganese trioxide / iron oxide (Mn2O3 / Fe2O3) composite cathode material for aqueous zinc-ion batteries using manganese ore tailings leachate. Background Technology

[0002] With the rapid development of the manganese industry, high-grade manganese ore has been extensively exploited, leading to the gradual depletion of high-grade manganese mines and a widening manganese ore shortage, while a large amount of manganese tailings are produced. Currently, the resource utilization rate of manganese tailings is low, mainly used for tailings reprocessing, fertilizer preparation, and building materials. However, about 80% of manganese tailings are stored in tailings ponds for extended periods, occupying significant land resources, polluting the environment, and wasting valuable elements (Mn, Fe, Si, Al, etc.). Therefore, exploring technologies for the resource utilization of manganese tailings is particularly important. Manganese in manganese tailings mainly exists in the form of MnO2. MnO2 has strong oxidizing properties under acidic conditions, and a reducing medium must be added to allow manganese to enter the solution. Glucose has been proven to be a very effective reducing agent. Direct reduction leaching of manganese tailings using glucose-acid (hydrochloric acid, sulfuric acid) yields a leachate containing large amounts of manganese, iron, and excess glucose. Therefore, the low-cost and efficient utilization of components in the reducing leaching solution of manganese ore tailings to prepare manganese-based products is of great significance for the further development of my country's manganese-based product industry. Accordingly, this invention proposes a method for preparing manganese trioxide / iron oxide composite cathode materials for aqueous zinc-ion batteries using manganese ore tailings leaching solution. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing a manganese trioxide / iron oxide composite cathode material for aqueous zinc-ion batteries using manganese ore tailings leachate.

[0004] The specific steps are as follows:

[0005] (1) A reduction leaching reaction was carried out using manganese tailings as raw material, glucose as reducing agent, and hydrochloric acid as leaching agent. After the reaction, the manganese tailings leachate was obtained by filtration and washing. The molar concentration of manganese ions in the leachate was determined to be 0.106 mol / L, the molar concentration of iron ions was 0.051 mol / L, and the molar concentration of glucose was 0.018 mol / L.

[0006] (2) Take 30 mL of the leachate obtained in step (1), add glucose to it, and adjust the molar ratio of manganese ions to glucose in the solution to (2~5):1.

[0007] (3) Transfer the solution obtained in step (2) to a crucible and place it in a muffle furnace to heat to 600 ℃ (heating rate is 5 ℃ / min) and keep it at that temperature for 3 hours. After cooling with the furnace, the Mn2O3 / Fe2O3 composite cathode material is obtained.

[0008] The method of this invention is simple to operate, the conditions are easy to control, the product yield is high, the production cost is low, and it is suitable for large-scale industrial production. Moreover, the prepared Mn2O3 / Fe2O3 composite cathode material has good zinc storage electrochemical performance. Attached Figure Description

[0009] Figure 1 The XRD patterns are those of the Mn2O3 / Fe2O3 composite cathode materials prepared in Examples 1-4.

[0010] Figure 2 The image shows a SEM image of the Mn2O3 / Fe2O3 composite cathode material prepared in Example 1.

[0011] Figure 3 The image shows a SEM image of the Mn2O3 / Fe2O3 composite cathode material prepared in Example 2.

[0012] Figure 4 The image shows a SEM image of the Mn2O3 / Fe2O3 composite cathode material prepared in Example 3.

[0013] Figure 5 The image shows a SEM image of the Mn2O3 / Fe2O3 composite cathode material prepared in Example 4.

[0014] Figure 6 The cycling performance curves of the Mn2O3 / Fe2O3 composite cathode materials prepared in Examples 1-4 at a current density of 0.5 A / g are shown.

[0015] Figure 7 The cycling performance curves of the Mn2O3 / Fe2O3 composite cathode materials prepared in Examples 1-4 at a current density of 1.0 A / g are shown.

[0016] Figure 8 Rate performance curves of the Mn2O3 / Fe2O3 composite cathode materials prepared in Examples 1-4 at different current densities (0.2, 0.5, 1.0, 2.0, 1.0, 0.5, 0.2 A / g). Detailed Implementation

[0017] The present invention will be further described below with reference to specific embodiments. It should be noted that the following embodiments are for the purpose of enabling those skilled in the art to better understand the present invention, and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments based on the above content.

[0018] Example 1:

[0019] (1) A reduction leaching reaction was carried out using manganese tailings as raw material, glucose as reducing agent, and hydrochloric acid as leaching agent. After the reaction, the manganese tailings leachate was obtained by filtration and washing. The molar concentration of manganese ions in the leachate was determined to be 0.106 mol / L, the molar concentration of iron ions was 0.051 mol / L, and the molar concentration of glucose was 0.018 mol / L.

[0020] (2) Take 30 mL of the leachate obtained in step (1), add glucose to it, and adjust the molar ratio of manganese ions to glucose in the solution to 5:1.

[0021] (3) Transfer the solution obtained in step (2) to a crucible and place it in a muffle furnace to heat to 600 ℃ (heating rate is 5 ℃ / min) and keep it at that temperature for 3 hours. After cooling with the furnace, the Mn2O3 / Fe2O3 composite cathode material is obtained.

[0022] Example 2:

[0023] (1) A reduction leaching reaction was carried out using manganese tailings as raw material, glucose as reducing agent, and hydrochloric acid as leaching agent. After the reaction, the manganese tailings leachate was obtained by filtration and washing. The molar concentration of manganese ions in the leachate was determined to be 0.106 mol / L, the molar concentration of iron ions was 0.051 mol / L, and the molar concentration of glucose was 0.018 mol / L.

[0024] (2) Take 30 mL of the leachate obtained in step (1), add glucose to it, and adjust the molar ratio of manganese ions to glucose in the solution to 4:1.

[0025] (3) Transfer the solution obtained in step (2) to a crucible and place it in a muffle furnace to heat to 600 ℃ (heating rate is 5 ℃ / min) and keep it at that temperature for 3 hours. After cooling with the furnace, the Mn2O3 / Fe2O3 composite cathode material is obtained.

[0026] Example 3:

[0027] (1) A reduction leaching reaction was carried out using manganese tailings as raw material, glucose as reducing agent, and hydrochloric acid as leaching agent. After the reaction, the manganese tailings leachate was obtained by filtration and washing. The molar concentration of manganese ions in the leachate was determined to be 0.106 mol / L, the molar concentration of iron ions was 0.051 mol / L, and the molar concentration of glucose was 0.018 mol / L.

[0028] (2) Take 30 mL of the leachate obtained in step (1), add glucose to it, and adjust the molar ratio of manganese ions to glucose in the solution to 3:1.

[0029] (3) Transfer the solution obtained in step (2) to a crucible and place it in a muffle furnace to heat to 600 ℃ (heating rate is 5 ℃ / min) and keep it at that temperature for 3 hours. After cooling with the furnace, the Mn2O3 / Fe2O3 composite cathode material is obtained.

[0030] Example 4:

[0031] (1) A reduction leaching reaction was carried out using manganese tailings as raw material, glucose as reducing agent, and hydrochloric acid as leaching agent. After the reaction, the manganese tailings leachate was obtained by filtration and washing. The molar concentration of manganese ions in the leachate was determined to be 0.106 mol / L, the molar concentration of iron ions was 0.051 mol / L, and the molar concentration of glucose was 0.018 mol / L.

[0032] (2) Take 30 mL of the leachate obtained in step (1), add glucose to it, and adjust the molar ratio of manganese ions to glucose in the solution to 2:1.

[0033] (3) Transfer the solution obtained in step (2) to a crucible and place it in a muffle furnace to heat to 600 ℃ (heating rate is 5 ℃ / min) and keep it at that temperature for 3 hours. After cooling with the furnace, the Mn2O3 / Fe2O3 composite cathode material is obtained.

[0034] Electrochemical performance testing:

[0035] The Mn2O3 / Fe2O3 composite cathode material, conductive carbon black (Super P), and polyvinylidene fluoride (PVDF) prepared in the examples were weighed out in a mass ratio of 7:2:1, mixed and ground evenly in a mortar, and an appropriate amount of N-methyl-2-pyrrolidone (NMP) was added to form a uniform slurry. This slurry was then evenly coated onto steel foil using a coater and vacuum dried at 80 °C for 12 hours. The coated slurry was then cut into 1×1 cm electrode sheets. Using the electrode sheets obtained above as the working electrode, a zinc sheet as the counter electrode, a glass fiber membrane (GF / D) as the separator, and a mixture of 2.0 mol / L ZnSO4 and 0.5 mol / L MnSO4 as the electrolyte, CR2025 coin cells were assembled in air. The constant current charge-discharge performance and rate performance of the battery were tested using a BTS-5V / 10mA charge-discharge tester from Shenzhen Xinwei Company, with a charge-discharge voltage range of 0.8~1.9 V. The current densities for rate performance testing were 0.2 A / g, 0.5 A / g, 1.0 A / g, 2.0 A / g, 1.0 A / g, 0.5 A / g, and 0.2 A / g, respectively, while the current densities for cycle performance testing were 0.5 A / g and 1.0 A / g, respectively. Before conducting the rate and cycle performance tests, the samples were first cycled 50 times at a current density of 0.15 A / g. The results of the zinc storage electrochemical performance tests for samples from Examples 1-4 are listed in Tables 1 and 2.

[0036]

[0037] Table 1: Rate performance test results of samples from Examples 1-4

[0038] Table 2: Cyclic performance test results of samples from Examples 1-4

[0039]

[0040] As shown in Tables 1 and 2, the cathode materials prepared in Examples 1-4 exhibit good rate performance and cycle stability. A comparison of the four examples reveals that Example 3 demonstrates relatively better rate performance and cycle stability.

[0041] like Figure 1 The figure shows the XRD patterns of the samples prepared in Examples 1-4. As can be seen from the figures, all prepared samples consist of only two phases, Mn2O3 and Fe2O3, with no other obvious impurity phases formed, indicating that the present invention successfully prepared the Mn2O3 / Fe2O3 composite cathode material.

[0042] like Figures 2-5The image shows SEM images of the Mn2O3 / Fe2O3 composite cathode materials prepared in Examples 1-4. As can be seen from the images, the Mn2O3 / Fe2O3 composite cathode materials prepared in this invention consist of aggregates of varying sizes composed of irregularly shaped large particles and several small particles.

[0043] like Figure 6 and Figure 7 The figure shows the cycling performance curves of the Mn2O3 / Fe2O3 composite cathode materials prepared in Examples 1-4 at current densities of 0.5 A / g and 1.0 A / g. As can be seen from the figure, the Mn2O3 / Fe2O3 composite cathode material prepared in Example 3 of this invention has a relatively higher charge-discharge specific capacity and better electrochemical cycling stability.

[0044] like Figure 8 The figure shows the rate performance curves of the Mn2O3 / Fe2O3 composite cathodes prepared in Examples 1-4 at different current densities (0.2 A / g, 0.5 A / g, 1 A / g, 2 A / g, 1 A / g, 0.5 A / g, 0.2 A / g). It can be seen from the figure that Example 3 exhibits relatively better rate performance.

Claims

1. A method for preparing Mn2O3 / Fe2O3 composite cathode material for aqueous zinc-ion batteries using manganese ore tailings leaching solution, characterized in that... The specific steps are as follows: (1) A reduction leaching reaction was carried out using manganese tailings as raw material, glucose as reducing agent, and hydrochloric acid as leaching agent. After the reaction, the manganese tailings leachate was obtained by filtration and washing. The molar concentration of manganese ions in the leachate was determined to be 0.106 mol / L, the molar concentration of iron ions was 0.051 mol / L, and the molar concentration of glucose was 0.018 mol / L. (2) Take 30 mL of the leachate obtained in step (1), add glucose to it, and adjust the molar ratio of manganese ions to glucose in the solution to (2~5):1; (3) Transfer the solution obtained in step (2) to a crucible and place it in a muffle furnace to heat to 600 °C at a heating rate of 5 °C / min and keep it at that temperature for 3 hours. After cooling with the furnace, the Mn2O3 / Fe2O3 composite cathode material is obtained.

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