Battery-type supercapacitor electrode material and preparation method thereof

Abstract

This invention belongs to the field of electrode material preparation technology, specifically relating to a battery-type supercapacitor electrode material and its preparation method. The electrode material is copper sulfide grown on cobalt tetrasulfide nickel, including the following steps: placing copper chloride dihydrate and thiourea with cobalt tetrasulfide nickel in a solvent, carrying out a solvothermal reaction at 140-180°C, and performing post-treatment to obtain a flower-shaped copper sulfide / cobalt tetrasulfide nickel composite material, which can be used as a battery-type electrode material in hybrid supercapacitors.

Description

Technical Field

[0001] This invention belongs to the field of electrode material preparation technology, specifically relating to a battery-type supercapacitor electrode material and its preparation method. Background Technology

[0002] Low specific energy is a bottleneck problem hindering the practical application of supercapacitors. Currently, the specific energy of commercially available supercapacitors is generally only 3-5 Wh / kg. -1 Lithium-ion batteries, on the other hand, can have a specific energy of up to 300–500 Wh / kg. -1 To effectively improve the performance of supercapacitors, hybrid supercapacitors have gradually come into focus. Hybrid supercapacitors contain both battery-type and capacitor-type electrodes, with the battery-type electrodes acting as the energy source and the capacitor-type electrodes as the power source. This endows hybrid supercapacitors with high specific energy and high specific power, bringing hope for achieving high-performance supercapacitors. Electrode materials are a decisive factor affecting supercapacitor performance, as they, along with the electrolyte decomposition voltage, dominate the capacitor's specific energy. Simultaneously, the conductivity of the electrode materials plays a crucial role in the specific power of the supercapacitor, and the microstructure of the electrode materials determines their cycle stability during practical use. Therefore, developing electrode materials with excellent capacitive properties is a key technological step in assembling high-performance hybrid supercapacitors.

[0003] Nickel-cobalt tetrasulfide is a classic electrode material for supercapacitors. In alkaline electrolytes, it can provide a large specific capacitance, but the discharge potential window is limited to 0.6V, which is not conducive to assembling high-performance supercapacitor devices. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a battery-type supercapacitor electrode material and its preparation method. This method enables the growth of copper sulfide on nickel tetracobalt sulfide, and the composite material retains its flower-shaped morphology while providing a large potential window and high specific capacitance.

[0005] To achieve the objectives of this invention, the inventors conducted numerous experiments and ultimately obtained the following technical solution: a method for preparing a wide-potential-window, high-capacity copper sulfide / cobalt tetrasulfide nickel composite material. First, cobalt tetrasulfide nickel is prepared by combining solvothermal and hydrothermal methods. Then, copper sulfide is grown on the cobalt tetrasulfide nickel using a solvothermal method, ultimately obtaining a battery-type copper sulfide / cobalt tetrasulfide nickel composite electrode material with a wide potential window and high capacity.

[0006] The present invention is specifically implemented through the following technical solution.

[0007] The first objective of this invention is to provide a method for preparing an electrode material for a battery-type supercapacitor, wherein the electrode material is copper sulfide grown on cobalt tetrasulfide nickel, comprising the following steps:

[0008] Copper chloride dihydrate and thiourea were placed in a solvent and subjected to a solvothermal reaction at 140–180 °C to grow copper sulfide on the nickel tetracobalt sulfide. After post-treatment, a copper sulfide / nickel tetracobalt sulfide composite material was obtained.

[0009] In some embodiments of the present invention, the molar ratio of the generated copper sulfide to nickel cobalt tetrasulfide is 1:0.33 to 4.

[0010] In some embodiments of the present invention, the molar ratio of copper chloride dihydrate to thiourea is 1:2.2 for every 1 mol of copper sulfide produced.

[0011] In some embodiments of the present invention, the solvent is anhydrous ethanol or water, preferably anhydrous ethanol.

[0012] In some embodiments of the present invention, the reaction time is 10 to 12 hours.

[0013] In some embodiments of the present invention, the temperature of the solvothermal reaction is 160°C and the reaction time is 12 h.

[0014] In some embodiments of the present invention, post-treatment refers to cooling the reaction system, filtering, washing the solid with water, washing with alcohol, and drying.

[0015] In some embodiments of the present invention, the nickel cobalt tetrasulfide is prepared by the following method:

[0016] Layered nickel-cobalt hydroxide was prepared by a solvothermal method using nickel nitrate, cobalt nitrate, and urea as precursors and ethanol as solvent; then, nickel dicobalt tetrasulfide was prepared by a hydrothermal method using layered nickel-cobalt hydroxide and sodium sulfide nonahydrate as reactants.

[0017] A second objective of this invention is to provide a battery-type supercapacitor electrode material prepared by the above-described preparation method.

[0018] In some embodiments of the present invention, the electrode material is copper sulfide grown on cobalt tetrasulfide nickel to form a copper sulfide / cobalt tetrasulfide nickel composite material, the composite material being flower-shaped.

[0019] In some embodiments of the present invention, the potential window of the electrode material is 1.35-1.52V, and the specific capacitance is 498-1091 C·g. -1 .

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] Regarding nickel cobalt tetrasulfide (CTS) supercapacitor electrode materials, while some research has been conducted, most studies have focused on using CTS as the positive electrode to assemble asymmetric supercapacitors. This invention shifts the research focus to improving the potential window of CTS-based electrode materials, thereby enhancing the performance of CTS supercapacitor electrode materials. Specifically:

[0022] (1) This invention utilizes a solvothermal reaction condition to allow copper sulfide to grow directly on nickel cobalt tetrasulfide, ultimately forming a flower-shaped copper sulfide / nickel cobalt tetrasulfide composite material, which is used as a supercapacitor electrode with a specific capacitance of 498–1091 C·g. -1 With a potential window as high as 1.52V, it can be used as a battery-type electrode material in the assembly of high-performance hybrid supercapacitors.

[0023] (2) The specific capacity and potential window of the copper sulfide / cobalt tetrasulfide nickel composite material prepared by the present invention can be controlled: it can be found by constant current charge and discharge curves that the method of the present invention can effectively control the specific capacity and potential window of the composite material by controlling the molar ratio of copper sulfide and cobalt tetrasulfide nickel, and obtain a composite material with excellent capacitance properties.

[0024] (3) The method of the present invention has mild reaction conditions, short time, readily available raw materials, strong operability, low preparation cost, and is suitable for large-scale production application. Attached Figure Description

[0025] Figure 1 The X-ray photoelectron spectroscopy of the copper sulfide / cobalt tetrasulfide nickel composite material prepared in Example 1 is shown.

[0026] Figure 2 This is the X-ray diffraction pattern of the copper sulfide / cobalt tetrasulfide nickel composite material prepared in Example 1;

[0027] Figure 3 Here is a scanning electron microscope image of the copper sulfide / cobalt tetrasulfide nickel composite material prepared in Example 1;

[0028] Figure 4 The constant current charge-discharge curves of the copper sulfide / cobalt tetrasulfide nickel composite material prepared in Example 1 are shown.

[0029] Figure 5 The X-ray diffraction pattern and constant current charge-discharge curve of the copper sulfide / cobalt tetrasulfide nickel composite material prepared in Example 2 are shown.

[0030] Figure 6 The X-ray diffraction pattern and constant current charge-discharge curve of the copper sulfide / cobalt tetrasulfide nickel composite material prepared in Example 3 are shown.

[0031] Figure 7 The X-ray diffraction pattern and constant current charge-discharge curve of the copper sulfide / cobalt tetrasulfide nickel composite material prepared in Example 4 are shown.

[0032] Figure 8 The X-ray diffraction pattern and constant current charge-discharge curve of the copper sulfide / cobalt tetrasulfide nickel composite material prepared in Example 5 are shown. Detailed Implementation

[0033] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and accompanying drawings. However, the embodiments described are not intended to limit the present invention.

[0034] Unless otherwise specified, the experimental and detection methods described in the following embodiments are conventional methods; unless otherwise specified, the reagents and materials are commercially available.

[0035] Low specific energy is a bottleneck problem in the field of supercapacitors. The most effective way to improve the specific energy of supercapacitors is to broaden their operating voltage, and fabricating electrode materials with a wide potential window is an effective method to obtain capacitors with high operating voltages. Cobalt tetrasulfide (NiTe) is a classic supercapacitor electrode material. In alkaline electrolytes, it can provide a large specific capacitance, but its discharge potential window is limited to 0.6V, which is not conducive to assembling high-performance supercapacitor devices. In recent years, although researchers have carried out some research on NiTe electrode materials, most of this work has focused on using NiTe as the positive electrode to assemble asymmetric supercapacitors, with relatively little work on improving the potential window of NiTe-based electrode materials.

[0036] Therefore, this invention utilizes a solvothermal reaction condition to allow copper sulfide to grow directly on nickel cobalt tetrasulfide, ultimately forming a flower-shaped copper sulfide / nickel cobalt tetrasulfide composite material, which is then used as an electrode for a supercapacitor. The raw material for preparing copper sulfide and nickel cobalt tetrasulfide are placed in a solvent and subjected to a solvothermal reaction at 140–180°C, followed by post-treatment to obtain the copper sulfide / nickel cobalt tetrasulfide composite material.

[0037] Both copper sulfide and nickel cobalt tetrasulfide exhibit capacitive properties in alkaline electrolysis, and their potential windows are complementary. Experiments have shown that the copper sulfide / nickel cobalt tetrasulfide composite electrode can achieve a discharge potential window of up to 1.52V in alkaline electrolytes, which is significantly higher than the potential window of the nickel cobalt tetrasulfide electrode (0.6V).

[0038] The specific capacity and potential window of the copper sulfide / cobalt tetrasulfide nickel composite material prepared by this invention can be controlled: it can be found by constant current charge-discharge curves that by controlling the molar ratio of copper sulfide and cobalt tetrasulfide nickel, the specific capacity and potential window of the composite material can be effectively controlled, and a composite material with excellent capacitance properties can be obtained.

[0039] The present invention will now be described in detail through specific embodiments and comparative examples.

[0040] Example 1

[0041] A method for preparing electrode material for a battery-type supercapacitor includes the following steps:

[0042] Step 1: Preparation of Cobalt Tetrasulfide Nickel Powder

[0043] (1) Preparation of layered nickel-cobalt bimetallic hydroxide. 1.8275 g nickel nitrate hexahydrate, 1.394 g cobalt nitrate hexahydrate and 3.4510 g urea were added to 70 mL of anhydrous ethanol and ultrasonicated for 10 min in an ultrasonic cleaner to fully dissolve them. The mixture was then transferred to a 100 mL reaction vessel and reacted at 120 °C in a forced-air drying oven for 10 h. After complete cooling, the mixture was filtered, washed with water, then washed with anhydrous ethanol, and dried to obtain a pinkish-purple layered nickel-cobalt bimetallic hydroxide.

[0044] (2) Weigh 0.4g of layered nickel-cobalt bimetallic hydroxide and 2.112g of sodium sulfide nonahydrate and dissolve them in 60mL of deionized water. Place the system in a forced-air drying oven and react at 180℃ for 7 hours. After complete cooling, filter the mixture and wash it thoroughly with distilled water. After drying, obtain black cobalt tetrasulfide nickel powder.

[0045] Step 2: Preparation of copper sulfide / cobalt tetrasulfide nickel composite material

[0046] 0.1422 g of copper chloride dihydrate, 0.1464 g of thiourea, and 0.1234 g of nickel cobalt tetrasulfide were dispersed in 60 mL of anhydrous ethanol and ultrasonically treated for 15 min in an ultrasonic cleaner to ensure complete mixing. The mixture was then transferred to a 100 mL high-temperature reactor and reacted at 160 °C in a forced-air drying oven for 10 h. After complete cooling, the mixture was filtered. The resulting product was washed with water and then with ethanol. After drying, a black copper sulfide / nickel cobalt tetrasulfide composite material was obtained.

[0047] The product obtained in Example 1 was characterized and tested using X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, and an electrochemical workstation. The results are shown in the figure. Figures 1-4 .

[0048] Depend on Figure 1X-ray photoelectron spectroscopy revealed the presence of Cu, Ni, Co, and S elements in the composite material. Figure 2 The X-ray diffraction pattern shows that the product contains characteristic diffraction peaks of cubic CuS and cubic NiCo2S4 phases. Figure 3 The FESEM images show that the copper sulfide / cobalt dinickel sulfide composite exhibits a flower-like morphology with a diameter of approximately 9 μm. Therefore, the prepared material is a flower-like copper sulfide / cobalt dinickel sulfide composite. Figure 4 The galvanostatic charge-discharge curves show that the obtained product electrode exhibits a well-symmetrical shape, indicating good capacitive properties. Within the voltage range of -1.12 to 0.38 V vs. SCE, at a current density of 1 A·g... -1 At that time, its specific capacity reached 1091 C·g. -1 It can be used as an electrode material for battery-type supercapacitors, with a potential window as high as 1.5V.

[0049] Example 2

[0050] A method for preparing electrode material for a battery-type supercapacitor includes the following steps:

[0051] Step 1: Preparation of Cobalt Tetrasulfide Nickel Powder

[0052] (1) Preparation of layered nickel-cobalt bimetallic hydroxide. 1.8275 g nickel nitrate hexahydrate, 1.394 g cobalt nitrate hexahydrate and 3.4510 g urea were added to 70 mL of anhydrous ethanol and ultrasonicated for 10 min in an ultrasonic cleaner to fully dissolve them. The mixture was then transferred to a 100 mL reaction vessel and reacted at 120 °C in a forced-air drying oven for 10 h. After complete cooling, the mixture was filtered, washed with water, then washed with anhydrous ethanol, and dried to obtain a pinkish-purple layered nickel-cobalt bimetallic hydroxide.

[0053] (2) Weigh 0.4g of layered nickel-cobalt bimetallic hydroxide and 2.112g of sodium sulfide nonahydrate and dissolve them in 60mL of deionized water. Place the system in a forced-air drying oven and react at 180℃ for 7 hours. After complete cooling, filter the mixture and wash it thoroughly with distilled water. After drying, obtain black cobalt tetrasulfide nickel powder.

[0054] Step 2: Preparation of copper sulfide / cobalt tetrasulfide nickel composite material

[0055] 0.1422 g of copper chloride dihydrate, 0.1464 g of thiourea, and 0.4936 g of nickel cobalt tetrasulfide were dispersed in 60 mL of anhydrous ethanol and ultrasonically treated for 15 min in an ultrasonic cleaner to ensure complete mixing. The mixture was then transferred to a 100 mL high-temperature reactor and reacted at 160 °C in a forced-air drying oven for 10 h. After complete cooling, the mixture was filtered, and the resulting product was washed with water and then with ethanol. After drying, a black copper sulfide / nickel cobalt tetrasulfide composite material was obtained. The X-ray diffraction pattern and constant current charge-discharge characteristics of the prepared copper sulfide / nickel cobalt tetrasulfide composite material are shown below. Figure 5 As shown, tests were conducted within the voltage range of -1.0 to 0.37V vs. SCE, when the current density was 1A·g -1 At that time, its specific capacitance was 790 C·g. -1 The potential window is as high as 1.37V.

[0056] Example 3

[0057] A method for preparing electrode material for a battery-type supercapacitor includes the following steps:

[0058] Step 1: Preparation of Cobalt Tetrasulfide Nickel Powder

[0059] (1) Preparation of layered nickel-cobalt bimetallic hydroxide. 1.8275 g nickel nitrate hexahydrate, 1.394 g cobalt nitrate hexahydrate and 3.4510 g urea were added to 70 mL of anhydrous ethanol and ultrasonicated for 10 min in an ultrasonic cleaner to fully dissolve them. The mixture was then transferred to a 100 mL reaction vessel and reacted at 120 °C in a forced-air drying oven for 10 h. After complete cooling, the mixture was filtered, washed with water, then washed with anhydrous ethanol, and dried to obtain a pinkish-purple layered nickel-cobalt bimetallic hydroxide.

[0060] (2) Weigh 0.4g of layered nickel-cobalt bimetallic hydroxide and 2.112g of sodium sulfide nonahydrate and dissolve them in 60mL of deionized water. Place the system in a forced-air drying oven and react at 180℃ for 7 hours. After complete cooling, filter the mixture and wash it thoroughly with distilled water. After drying, obtain black cobalt tetrasulfide nickel powder.

[0061] Step 2: Preparation of copper sulfide / cobalt tetrasulfide nickel composite material

[0062] 0.4266 g of copper chloride dihydrate, 0.5856 g of thiourea, and 0.1234 g of nickel cobalt tetrasulfide were dispersed in 60 mL of anhydrous ethanol and ultrasonically treated for 15 min in an ultrasonic cleaner to ensure complete mixing. The mixture was then transferred to a 100 mL high-temperature reactor and reacted at 160 °C for 10 h in a forced-air drying oven. After complete cooling, the mixture was filtered, and the resulting product was washed with water and then with ethanol. After drying, a black copper sulfide / nickel cobalt tetrasulfide composite material was obtained. The X-ray diffraction pattern and constant current charge-discharge characteristics of the prepared copper sulfide / nickel cobalt tetrasulfide composite material are shown below. Figure 6 As shown, tests were conducted within the voltage range of -1.15 to 0.37V vs. SCE, when the current density was 1A·g -1 At that time, its specific capacitance was 498 C·g. -1 The potential window is as high as 1.52V.

[0063] Example 4

[0064] A method for preparing electrode material for a battery-type supercapacitor includes the following steps:

[0065] Step 1: Preparation of Cobalt Tetrasulfide Nickel Powder

[0066] (1) Preparation of layered nickel-cobalt bimetallic hydroxide. 1.8275 g nickel nitrate hexahydrate, 1.394 g cobalt nitrate hexahydrate and 3.4510 g urea were added to 70 mL of anhydrous ethanol and ultrasonicated for 10 min in an ultrasonic cleaner to fully dissolve them. The mixture was then transferred to a 100 mL reaction vessel and reacted at 120 °C in a forced-air drying oven for 10 h. After complete cooling, the mixture was filtered, washed with water, then washed with anhydrous ethanol, and dried to obtain a pinkish-purple layered nickel-cobalt bimetallic hydroxide.

[0067] (2) Weigh 0.4g of layered nickel-cobalt bimetallic hydroxide and 2.112g of sodium sulfide nonahydrate and dissolve them in 60mL of deionized water. Place the system in a forced-air drying oven and react at 180℃ for 7 hours. After complete cooling, filter the mixture and wash it thoroughly with distilled water. After drying, obtain black cobalt tetrasulfide nickel powder.

[0068] Step 2: Preparation of copper sulfide / cobalt tetrasulfide nickel composite material

[0069] In this embodiment, the hydrothermal reaction was carried out at 140℃ for 12 hours, and the other steps were the same as in Example 1. The X-ray diffraction pattern and constant current charge-discharge parameters of the prepared copper sulfide / cobalt tetrasulfide nickel composite material were obtained. Figure 7 As shown, the test results showed that within the voltage range of -1.12 to 0.37V vs. SCE, when the current density was 1A·g -1 At that time, its specific capacity reached 542 C·g. -1 The potential window is as high as 1.49V.

[0070] Example 5

[0071] A method for preparing electrode material for a battery-type supercapacitor includes the following steps:

[0072] Step 1: Preparation of Cobalt Tetrasulfide Nickel Powder

[0073] (1) Preparation of layered nickel-cobalt bimetallic hydroxide. 1.8275 g nickel nitrate hexahydrate, 1.394 g cobalt nitrate hexahydrate and 3.4510 g urea were added to 70 mL of anhydrous ethanol and ultrasonicated for 10 min in an ultrasonic cleaner to fully dissolve them. The mixture was then transferred to a 100 mL reaction vessel and reacted at 120 °C in a forced-air drying oven for 10 h. After complete cooling, the mixture was filtered, washed with water, then washed with anhydrous ethanol, and dried to obtain a pinkish-purple layered nickel-cobalt bimetallic hydroxide.

[0074] (2) Weigh 0.4g of layered nickel-cobalt bimetallic hydroxide and 2.112g of sodium sulfide nonahydrate and dissolve them in 60mL of deionized water. Place the system in a forced-air drying oven and react at 180℃ for 7 hours. After complete cooling, filter the mixture and wash it thoroughly with distilled water. After drying, obtain black cobalt tetrasulfide nickel powder.

[0075] Step 2: Preparation of copper sulfide / cobalt tetrasulfide nickel composite material

[0076] In this embodiment, the hydrothermal reaction was carried out at 180℃ for 12 hours, and other steps were the same as in Example 1. The X-ray diffraction pattern and constant current charge-discharge parameters of the copper sulfide / cobalt tetrasulfide nickel composite material were obtained. Figure 8 As shown, tests were conducted within the voltage range of -0.98 to 0.37 V vs. SCE, when the current density was 1 A·g -1 At that time, its specific capacitance was 696 C·g. -1 The potential window is as high as 1.35V.

[0077] Comparative Example 1

[0078] Based on Example 1, the molar ratio of nickel cobalt tetrasulfide to the generated copper sulfide was increased to 5. The specific steps are as follows:

[0079] Step 1: Preparation of Cobalt Tetrasulfide Nickel Powder

[0080] (1) Preparation of layered nickel-cobalt bimetallic hydroxide. 1.8275 g nickel nitrate hexahydrate, 1.394 g cobalt nitrate hexahydrate and 3.4510 g urea were added to 70 mL of anhydrous ethanol and ultrasonicated for 10 min in an ultrasonic cleaner to fully dissolve them. The mixture was then transferred to a 100 mL reaction vessel and reacted at 120 °C in a forced-air drying oven for 10 h. After complete cooling, the mixture was filtered, washed with water, then washed with anhydrous ethanol, and dried to obtain a pinkish-purple layered nickel-cobalt bimetallic hydroxide.

[0081] (2) Weigh 0.4g of layered nickel-cobalt bimetallic hydroxide and 2.112g of sodium sulfide nonahydrate and dissolve them in 60mL of deionized water. Place the system in a forced-air drying oven and react at 180℃ for 7 hours. After complete cooling, filter the mixture and wash it thoroughly with distilled water. After drying, obtain black cobalt tetrasulfide nickel powder.

[0082] Step 2: Preparation of copper sulfide / cobalt tetrasulfide nickel composite material

[0083] 0.1422 g of copper chloride dihydrate, 0.1464 g of thiourea, and 0.6170 g of nickel cobalt tetrasulfide were dispersed in 60 mL of anhydrous ethanol and ultrasonically treated for 15 min in an ultrasonic cleaner to ensure complete mixing. The mixture was then transferred to a 100 mL high-temperature reactor and reacted at 160 °C in a forced-air drying oven for 10 h. After complete cooling, the mixture was filtered, and the resulting product was washed with water and then with ethanol. After drying, a black copper sulfide / nickel cobalt tetrasulfide composite material was obtained.

[0084] Comparative Example 1 is based on Example 1, but the molar ratio of nickel cobalt tetrasulfide to copper sulfide is increased to 5, and the potential window of the prepared composite material is smaller (only 1.28V), which is less than 1.5V in Example 1.

[0085] Comparative Example 2

[0086] Based on Example 1, the molar ratio of copper sulfide to nickel cobalt tetrasulfide was increased to 3.5. The specific steps are as follows:

[0087] Step 1: Preparation of Cobalt Tetrasulfide Nickel Powder

[0088] (1) Preparation of layered nickel-cobalt bimetallic hydroxide. 1.8275 g nickel nitrate hexahydrate, 1.394 g cobalt nitrate hexahydrate and 3.4510 g urea were added to 70 mL of anhydrous ethanol and ultrasonicated for 10 min in an ultrasonic cleaner to fully dissolve them. The mixture was then transferred to a 100 mL reaction vessel and reacted at 120 °C in a forced-air drying oven for 10 h. After complete cooling, the mixture was filtered, washed with water, then washed with anhydrous ethanol, and dried to obtain a pinkish-purple layered nickel-cobalt bimetallic hydroxide.

[0089] (2) Weigh 0.4g of layered nickel-cobalt bimetallic hydroxide and 2.112g of sodium sulfide nonahydrate and dissolve them in 60mL of deionized water. Place the system in a forced-air drying oven and react at 180℃ for 7 hours. After complete cooling, filter the mixture and wash it thoroughly with distilled water. After drying, obtain black cobalt tetrasulfide nickel powder.

[0090] Step 2: Preparation of copper sulfide / cobalt tetrasulfide nickel composite material

[0091] 0.4977 g of copper chloride dihydrate, 0.5124 g of thiourea, and 0.1234 g of nickel cobalt tetrasulfide were dispersed in 60 mL of anhydrous ethanol and ultrasonically treated for 15 min in an ultrasonic cleaner to ensure complete mixing. The mixture was then transferred to a 100 mL high-temperature reactor and reacted at 160 °C in a forced-air drying oven for 10 h. After complete cooling, the mixture was filtered, and the resulting product was washed with water and then with ethanol. After drying, a black copper sulfide / nickel cobalt tetrasulfide composite material was obtained.

[0092] Comparative Example 2, based on Example 1, increased the molar ratio of copper sulfide to nickel cobalt tetrasulfide to 3.5. While the resulting composite material had a larger potential window (up to 1.60 V), its specific capacity decreased to 498 C g. -1 The following (specifically 450°C g) -1 The value is much smaller than 1091 C·g in Example 1. -1 .

[0093] Comparative Example 3

[0094] Based on Example 1, the hydrothermal reaction temperature was changed, and the specific steps are as follows:

[0095] Step 1: Preparation of Cobalt Tetrasulfide Nickel Powder

[0096] (1) Preparation of layered nickel-cobalt bimetallic hydroxide. 1.8275 g nickel nitrate hexahydrate, 1.394 g cobalt nitrate hexahydrate and 3.4510 g urea were added to 70 mL of anhydrous ethanol and ultrasonicated for 10 min in an ultrasonic cleaner to fully dissolve them. The mixture was then transferred to a 100 mL reaction vessel and reacted at 120 °C in a forced-air drying oven for 10 h. After complete cooling, the mixture was filtered, washed with water, then washed with anhydrous ethanol, and dried to obtain a pinkish-purple layered nickel-cobalt bimetallic hydroxide.

[0097] (2) Weigh 0.4g of layered nickel-cobalt bimetallic hydroxide and 2.112g of sodium sulfide nonahydrate and dissolve them in 60mL of deionized water. Place the system in a forced-air drying oven and react at 180℃ for 7 hours. After complete cooling, filter the mixture and wash it thoroughly with distilled water. After drying, obtain black cobalt tetrasulfide nickel powder.

[0098] Step 2: Preparation of copper sulfide / cobalt tetrasulfide nickel composite material

[0099] 0.1422 g of copper chloride dihydrate, 0.1464 g of thiourea, and 0.1234 g of nickel cobalt tetrasulfide were dispersed in 60 mL of anhydrous ethanol and ultrasonically treated for 15 min in an ultrasonic cleaner to ensure complete mixing. The mixture was then transferred to a 100 mL high-temperature reactor and reacted at 190 °C in a forced-air drying oven for 10 h. After complete cooling, the mixture was filtered, and the resulting product was washed with water and then with ethanol. After drying, a black copper sulfide / nickel cobalt tetrasulfide composite material was obtained.

[0100] Based on Example 1, the hydrothermal reaction temperature was changed to 190°C. It was found that when the hydrothermal reaction temperature was greater than 180°C (190°C), the potential window of the prepared composite material became smaller, all less than 1.3V (specifically 1.25V), which was less than 1.5V in Example 1. When the hydrothermal reaction temperature was higher than the temperature of this invention, compounds of other crystalline copper were formed, resulting in a narrower potential window for the material.

[0101] As can be seen from the above examples and comparative examples, by controlling the molar ratio of copper sulfide and nickel cobalt tetrasulfide, the specific capacitance and potential window of the composite material can be effectively controlled, resulting in a composite material with excellent capacitance properties; and when the reaction temperature is higher than 180℃, the potential window of the material narrows. Therefore, the copper sulfide / nickel cobalt tetrasulfide composite material prepared by this invention can achieve the preparation of a high-capacity composite material with a wide potential window under specific reaction conditions.

[0102] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, it is intended to include any modifications and variations that fall within the scope of the claims and their equivalents.

Claims

1. A method for preparing a battery-type supercapacitor electrode material, characterized by, The electrode material is copper sulfide grown on cobalt tetrasulfide nickel alloy, including the following steps: Copper chloride dihydrate and thiourea were placed in a solvent and subjected to a solvothermal reaction at 140–180 °C to grow copper sulfide on nickel tetracobalt sulfide. After post-treatment, a battery-type supercapacitor electrode material was obtained. The cobalt tetrasulfide nickel alloy is prepared by the following method: Layered nickel-cobalt hydroxide was prepared by a solvothermal method using nickel nitrate, cobalt nitrate, and urea as precursors and ethanol as solvent; then, nickel dicobalt tetrasulfide was prepared by a hydrothermal method using layered nickel-cobalt hydroxide and sodium sulfide nonahydrate as reactants.

2. The preparation method according to claim 1, characterized in that, The molar ratio of grown copper sulfide to nickel cobalt tetrasulfide is 1:0.33–4.

3. The preparation method according to claim 2, characterized in that, For every 1 mol of copper sulfide produced, the molar ratio of copper chloride dihydrate to thiourea is 1:2.

2.

4. The preparation method according to claim 1, characterized in that, The solvent is anhydrous ethanol or water.

5. The preparation method according to claim 1, characterized in that, The reaction time is 10–12 hours.

6. The preparation method according to claim 1, characterized in that, Post-treatment refers to the following steps after the reaction system is cooled: filtration, solid water washing followed by alcohol washing, and drying.

7. Battery-type supercapacitor electrode material prepared by the preparation method according to any one of claims 1-6.

8. The electrode material according to claim 7, characterized in that, The electrode material is a composite material formed by growing copper sulfide on nickel cobalt tetrasulfide, and the composite material is flower-shaped.

9. The electrode material according to claim 7, characterized in that, The potential window of the electrode material is 1.35-1.52V, and the specific capacitance is 498-1091C·g -1 .

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