High-capacity negative electrode material of secondary seawater battery and preparation method of high-capacity negative electrode material

Abstract

The invention discloses a high-capacity negative electrode material of a secondary seawater battery and a preparation method of the high-capacity negative electrode material. The material is low in cost, relatively high in specific capacity and good in cycling stability. The secondary seawater battery negative electrode Fe2O3 material is prepared through an electrochemical deposition method, the preparation process is simple and rapid, and the secondary seawater battery negative electrode Fe2O3 material is suitable for industrial mass production. The material can be used as a negative electrode material of a high-performance secondary seawater battery, and has important significance for developing a safe, environment-friendly, low-cost and large-scale energy storage technology capable of adapting to a marine environment.

Description

Technical Field

[0001] The invention belongs to the technical field of energy storage and material preparation, and specifically relates to a high-capacity negative electrode material for a secondary seawater battery and a preparation method thereof. Background Art

[0002] Seawater is the most ideal electrolyte for secondary batteries, with the advantages of zero cost, non-flammable, environmentally friendly, inexhaustible and inexhaustible. Current seawater batteries are mainly primary batteries and can no longer be recharged. The key to developing secondary seawater batteries is to design and prepare high-capacity seawater battery electrode materials. Although there are many studies on the supercapacitor performance of Fe2O3, its specific capacity in seawater is relatively low. In view of the above problems, the present invention designs and prepares Fe2O3 with high specific capacity as the negative electrode material of secondary seawater batteries, and proposes a preparation method for high-capacity Fe2O3 negative electrodes suitable for seawater batteries, which has a certain promoting effect on the development of low-cost and green energy storage technology. Summary of the invention

[0003] The purpose of the present invention is to develop a method for preparing a high-capacity Fe2O3 negative electrode material suitable for secondary seawater batteries. The preparation process has the advantages of low cost and rapidity, and is suitable for large-scale energy storage applications.

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

[0005] The invention discloses a high-capacity negative electrode material for a secondary seawater battery, which is a Fe2O3 material prepared by an electrodeposition method combined with heat treatment.

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

[0007] Furthermore, the potential during electrodeposition 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 (ie, the substrate material), and the positive electrode is graphite.

[0010] Furthermore, the substrate material is carbon paper or carbon cloth that has been heat-treated or not.

[0011] Furthermore, after the electrodeposition is completed, Fe2O3 is obtained by further heat treatment at a temperature of 280-350°C, preferably 300°C, and the time is usually 1-2 hours.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] Compared with other "supercapacitor" type negative electrodes or Fe2O3 prepared by other methods, this material can be used as a negative electrode material for secondary seawater batteries and has a high specific capacity. 2 The discharge specific capacity can reach 138 mAh / g. Compared with other secondary seawater battery negative electrode materials, this material has abundant element sources, low cost and simple preparation process. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0015] Figure 2 This is the Raman spectrum of the Fe2O3 secondary seawater battery negative electrode material prepared in Example 1 of the present invention;

[0016] Figure 3 This is the constant current charge and discharge curve of the Fe2O3 secondary seawater battery negative electrode material prepared in Example 1 of the present invention;

[0017] Figure 4 This is the cycle stability curve of the Fe2O3 secondary seawater battery negative electrode material prepared in Example 1 of the present invention;

[0018] Figure 5 This is the constant current charge and discharge curve of the Fe2O3 secondary seawater battery negative electrode material prepared in Example 2 of the present invention;

[0019] Figure 6 This is the constant current charge and discharge curve of the Fe2O3 secondary seawater battery negative electrode material prepared in Example 3 of the present invention;

[0020] Figure 7 This is the constant current charge and discharge curve of the Fe2O3 secondary seawater battery negative electrode material prepared in Example 4 of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose and technical solution of the present invention clearer and easier to understand, the present invention is described in detail below in conjunction with embodiments. It should be noted that the specific embodiments described herein are only used to explain the present invention and are not used to limit the scope of protection of the present invention.

[0022] Example 1

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

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

[0025] The scanning electron microscope photo of the Fe2O3 material prepared in this example is as follows: Figure 1 As shown. Raman spectroscopy results ( Figure 2 ) indicates that it is Fe2O3 phase. This material is used as negative electrode material to test its energy storage performance in a three-electrode system. The electrolyte is seawater. Its charge and discharge curve is as follows Figure 3 As shown, the current density is 1.25 mA / cm 2 The discharge capacity is as high as 130mAh / g; its cycle stability is as 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, which has the characteristics of charge and discharge.

[0026] Example 2

[0027] The carbon paper that was previously heat-treated at 450 degrees for 2 hours was used as the negative electrode, the graphite electrode was used as the positive electrode, and the electrolyte was 0.02 mol / L ferrous chloride solution. The Fe2O3 loaded on the carbon paper was deposited at a constant potential of 1.5V for 15 minutes. The obtained sample was cleaned and dried, and the sample was heat-treated at 300 degrees for 2 hours to obtain the desired material. The material was used as the negative electrode material, and its energy storage performance was tested in a three-electrode system. The electrolyte was seawater. Its charge and discharge curve is shown in the figure. Figure 5 As shown, the current density is 1.25 mA / cm 2 The discharge capacity is 138 mAh / g.

[0028] Example 3

[0029] The unheat-treated carbon paper was directly used as the negative electrode, the graphite electrode was used as the positive electrode, and the electrolyte was 0.02 mol / L ferrous chloride solution. The Fe2O3 loaded on the carbon paper was deposited at a constant potential of 1.5 V for 5 minutes. The obtained sample was cleaned and dried, and the sample was heat-treated at 300°C for 2 hours to obtain the desired material. The material was used as the negative electrode material, and its energy storage performance was tested in a three-electrode system. The electrode liquid was seawater. Its charge and discharge curve is shown in Figure 6 As shown, the current density is 1.25 mA / cm 2 The discharge capacity is 108 mAh / g.

[0030] Example 4

[0031] The unheat-treated carbon cloth was used as the negative electrode, the graphite electrode was used as the positive electrode, and the electrolyte was 0.02 mol / L ferrous chloride solution. The Fe2O3 loaded on the carbon cloth was deposited at a constant potential of 1.5 V for 5 minutes. The obtained sample was cleaned and dried, and the sample was heat-treated at 300°C for 2 hours to obtain the desired material. The material was used as the negative electrode material, and its energy storage performance was tested in a three-electrode system. The electrode liquid was seawater. Its charge and discharge curve is shown in the figure. Figure 7 As shown, the current density is 1.25 mA / cm 2 The discharge capacity is 125 mAh / g.

[0032] It should be understood that the embodiments described in this specification are only used to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, as an example and not a limitation, the alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly introduced and described in this specification.

[0033] The present invention illustrates the detailed preparation method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed preparation method, that is, it does not mean that the present invention must rely on the above-mentioned products and detailed preparation methods to be implemented. It should be clear to those skilled in the art that any improvement of the present invention, the combination or equivalent replacement of the raw materials of the product of the present invention, all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A high-capacity negative electrode material for a secondary seawater battery, characterized in that: It is a Fe2O3 material obtained by electrodeposition combined with heat treatment.

2. The high-capacity negative electrode material for secondary seawater batteries according to claim 1, characterized in that: The electrodeposition solution is a ferrous chloride solution with a concentration of 0.01-0.03 mol / L.

3. The high-capacity negative electrode material for secondary seawater batteries according to claim 1, characterized in that: The potential during electrodeposition was 1.3-1.6V.

4. The high-capacity negative electrode material for secondary seawater batteries according to claim 1, characterized in that: The substrate material used in the electrodeposition is carbon paper or carbon cloth.

5. The high-capacity negative electrode material for secondary seawater batteries according to claim 1, characterized in that: During electrodeposition, the base material is used as the negative electrode and graphite is used as the positive electrode.

6. The high-capacity negative electrode material for secondary seawater batteries according to claim 1, characterized in that: The heat treatment temperature is 280-350°C and the time is 1-2h.

7. A secondary seawater battery, characterized in that: Comprising the negative electrode material as described in any one of claims 1 to 6.

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