Secondary seawater battery high-capacity negative electrode material and preparation method thereof

Abstract

The application discloses a high-capacity negative electrode material of a secondary seawater battery and a preparation method of the material. The material has low cost, high specific capacity and good cycle stability. The secondary seawater battery negative electrode Fe2O3 material is prepared by an electrochemical deposition method, and the preparation process is simple and fast, and is suitable for industrialized mass production. The material can be used as the negative electrode material of a high-performance secondary seawater battery, and has important significance for developing safe, environment-friendly, low-cost and large-scale energy storage technology suitable for marine environment.

Description

Technical Field

[0001] This invention belongs to the field of energy storage and material preparation technology, specifically relating to a high-capacity negative electrode material for secondary seawater batteries and its preparation method. Background Technology

[0002] Seawater is the ideal electrolyte for rechargeable batteries, offering advantages such as zero cost, non-flammability, environmental friendliness, and inexhaustible availability. Current seawater batteries are primarily primary batteries and cannot be recharged. The key to developing rechargeable seawater batteries lies in designing and fabricating high-capacity electrode materials. While the supercapacitor performance of Fe2O3 has been extensively studied, its specific capacity in seawater is relatively low. To address this issue, this invention designs and prepares high-specific-capacity Fe2O3 as the negative electrode material for rechargeable seawater batteries and proposes a suitable method for preparing high-capacity Fe2O3 negative electrodes for seawater batteries, which will promote the development of low-cost, green energy storage technologies. Summary of the Invention

[0003] The purpose of this invention is to develop a method for preparing high-capacity Fe2O3 anode materials suitable for secondary seawater batteries. This preparation process has advantages such as low cost and speed, and is suitable for large-scale energy storage applications.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A high-capacity negative electrode material for secondary seawater batteries is Fe2O3 material prepared by electrodeposition combined with heat treatment.

[0006] Furthermore, in the electrodeposition method, the electrodeposition solution is a ferrous chloride solution with a concentration of 0.01-0.03 mol / L (preferably 0.02 mol / L), and electrodeposition is performed on the substrate material. The ferrous chloride solution is an aqueous solution of ferrous chloride.

[0007] Furthermore, the electrodeposition potential is 1.3-1.6V, preferably 1.5V.

[0008] Furthermore, the typical electrodeposition time is 5 to 15 minutes, and the electrodeposition time can be flexibly adjusted according to the material loading requirements, and is not limited to this electrodeposition time range.

[0009] Furthermore, during electrodeposition, the material is deposited onto the negative electrode (i.e., the substrate material), while the positive electrode is graphite.

[0010] Furthermore, the substrate material is carbon paper or carbon cloth, which may or may not have undergone heat treatment.

[0011] Furthermore, after electrodeposition, Fe2O3 is obtained by heat treatment. The heat treatment temperature is 280-350℃, preferably 300℃, and the time is usually 1-2 hours.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0013] Compared to other "supercapacitor" type anodes or Fe2O3 prepared by other methods, this material can be used as an anode material for secondary seawater batteries and has a high specific capacity. At a current density of 1.25 mA / cm²... 2 At this time, the discharge specific capacity can reach 138 mAh / g. Compared with other secondary seawater battery anode materials, this material has abundant element sources, low cost, and simple preparation process. Attached Figure Description

[0014] Figure 1 This is a scanning electron microscope image of the Fe2O3 secondary seawater battery anode material prepared in Example 1 of the present invention;

[0015] Figure 2 The Raman spectrum of the Fe2O3 secondary seawater battery anode material prepared in Example 1 of this invention;

[0016] Figure 3 The constant current charge-discharge curve of the Fe2O3 secondary seawater battery anode material prepared in Example 1 of this invention is shown.

[0017] Figure 4 The cycling stability curve of the Fe2O3 secondary seawater battery anode material prepared in Example 1 of this invention;

[0018] Figure 5 The constant current charge-discharge curve of the Fe2O3 secondary seawater battery anode material prepared in Example 2 of this invention is shown.

[0019] Figure 6 The constant current charge-discharge curve of the Fe2O3 secondary seawater battery anode material prepared in Example 3 of this invention is shown.

[0020] Figure 7 The constant current charge-discharge curves of the Fe2O3 secondary seawater battery anode material prepared in Example 4 of this invention are shown. Detailed Implementation

[0021] To make the objectives and technical solutions of this invention clearer and easier to understand, the invention will be described in detail below with reference to embodiments. It is worth noting that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of protection of this invention.

[0022] Example 1

[0023] A Fe2O3 material for the negative electrode of a secondary seawater battery, the preparation method of which includes the following steps:

[0024] Using carbon paper preheated to 450 degrees Celsius for 2 hours as the negative electrode and graphite electrode as the positive electrode, and 0.02 mol / L ferrous chloride solution as the electrolyte, Fe2O3 loaded on the carbon paper was obtained by deposition at a constant potential of 1.5 V for 5 minutes. After cleaning and drying the sample, the sample was heat-treated at 300 degrees Celsius for 2 hours to obtain the desired material.

[0025] Scanning electron microscope (SEM) images of the Fe2O3 material prepared in this embodiment are shown below. Figure 1 As shown. Raman spectroscopy results ( Figure 2 This indicates that it is a Fe2O3 phase. Using this material as the negative electrode, its energy storage performance was tested in a three-electrode system with seawater as the electrolyte. The charge-discharge curves are shown below. Figure 3 As shown, the current density is 1.25 mA / cm². 2 Its discharge capacity is as high as 130mAh / g; its cycle stability is as follows Figure 4 As shown, the specific capacity remains basically unchanged in the first 100 cycles, and the capacity retention rate is 42% after 1000 cycles, exhibiting rechargeable and dischargeable characteristics.

[0026] Example 2

[0027] Carbon paper pre-heat-treated at 450°C for 2 hours was used as the negative electrode, and a graphite electrode as the positive electrode. The electrolyte was a 0.02 mol / L ferrous chloride solution. Fe₂O₃ was deposited on the carbon paper at a constant potential of 1.5 V for 15 minutes. The resulting sample was cleaned, dried, and then heat-treated at 300°C for 2 hours to obtain the desired material. This material was used as the negative electrode, and its energy storage performance was tested in a three-electrode system using seawater as the electrolyte. The charge-discharge curves are shown below. Figure 5 As shown, the current density is 1.25 mA / cm². 2 The discharge capacity at that time was 138mAh / g.

[0028] Example 3

[0029] Untreated carbon paper was used directly as the negative electrode, and graphite electrode as the positive electrode. The electrolyte was a 0.02 mol / L ferrous chloride solution. Fe₂O₃ was deposited on the carbon paper at a constant potential of 1.5 V for 5 minutes. The resulting sample was cleaned, dried, and then heat-treated at 300℃ for 2 hours to obtain the desired material. This material was then used as the negative electrode, and its energy storage performance was tested in a three-electrode system using seawater as the electrode electrolyte. The charge-discharge curves are shown below. Figure 6 As shown, the current density is 1.25 mA / cm². 2 The discharge capacity at that time was 108 mAh / g.

[0030] Example 4

[0031] Untreated carbon cloth was used as the negative electrode, graphite electrode as the positive electrode, and 0.02 mol / L ferrous chloride solution as the electrolyte. Fe₂O₃ was deposited on the carbon cloth at a constant potential of 1.5 V for 5 minutes. The resulting sample was cleaned, dried, and then heat-treated at 300℃ for 2 hours to obtain the desired material. This material was used as the negative electrode, and its energy storage performance was tested in a three-electrode system using seawater as the electrode electrolyte. The charge-discharge curves are shown below. Figure 7 As shown, the current density is 1.25 mA / cm². 2 The discharge capacity at that time was 125mAh / g.

[0032] It should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments described herein. Other variations may also fall within the scope of this specification. Therefore, alternative configurations of the embodiments described herein are intended to be consistent with the teachings of this specification, rather than as examples or limitations. Accordingly, the embodiments described herein are not limited to those explicitly introduced and described herein.

[0033] The present invention has been illustrated with the above embodiments to explain the detailed preparation method of the present invention. However, the present invention is not limited to the above detailed preparation method, that is, it does not mean that the present invention must rely on the above product and detailed preparation method to be implemented. Those skilled in the art should understand that any improvement to the present invention, or the combination or equivalent substitution of the raw materials of the present invention, falls within the protection scope and disclosure scope of the present invention.

Claims

1. A secondary seawater battery, characterized in that, Fe2O3 material is prepared by electrodeposition and then heat-treated to obtain a negative electrode material. The electrolyte is seawater. The negative electrode material is a high-capacity negative electrode material. The electrodeposition potential is 1.3-1.6V and the heat treatment temperature is 280-350℃.

2. The secondary seawater battery according to claim 1, characterized in that, In the preparation of high-capacity anode materials, the electrodeposition solution is a ferrous chloride solution with a concentration of 0.01-0.03 mol / L.

3. The secondary seawater battery according to claim 1, characterized in that, In the preparation of high-capacity anode materials, the substrate material used during electrodeposition is carbon paper or carbon cloth.

4. The secondary seawater battery according to claim 1, characterized in that, In the electrodeposition of high-capacity anode materials, the substrate material is used as the anode and the positive electrode is graphite.

5. The secondary seawater battery according to claim 1, characterized in that, The heat treatment time for high-capacity anode materials is 1-2 hours.

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