Carbon-based coated composite copper oxide flexible electrode material and preparation method and application thereof

Abstract

The invention provides a carbon-based coated composite copper oxide flexible electrode material and a preparation method and application thereof. The copper oxide and cuprous oxide composite material is prepared in situ through thermal oxidation of foamy copper, and then the surface of the copper-based material is coated with the self-polymerized carbon-based material. The electrode material, a ternary all-lithium electrolyte and a lithium-silicon alloy negative electrode form a single thermal battery, the open-circuit voltage of the single thermal battery is 2.5 V-2. 8V, the open-circuit voltage of the single thermal battery is 2.1 V-2. 3V, no obvious voltage peak exists, the discharge voltage is stable, the discharge duration is longer than 80min when the cut-off voltage is 1.4 V under the conditions of 500 DEG C and 50mA constant-current discharge, and the single thermal battery is suitable for a long-life thermal battery. The conductivity of copper oxide is improved through carbon-based material coating, and the flexible electrode is not prone to fragmentation and suitable for being applied to a high-voltage long-service-life thermal battery in an extreme environment.

Description

Technical Field

[0001] The present invention belongs to the technical field of positive electrode materials for thermal batteries, and in particular relates to a carbon-based coated composite copper oxide flexible electrode material and a preparation method and application thereof. Background Art

[0002] Thermal batteries, also known as heat-activated storage batteries, are primary lithium batteries that use an electric spark to ignite an internal heating agent, instantly heating the solid electrolyte to melt and become an ionic conductor, allowing for discharge. Because the electrolyte is non-conductive in its solid state, it remains insulated when unactivated and prevents self-discharge, enabling long-term energy storage without degradation. Consequently, they are widely used in military equipment. Currently, the most commonly used cathode materials in thermal batteries include transition metal sulfides and oxides. FeS2 is the most commonly used cathode material in thermal batteries due to its ease of preparation and stable voltage. However, FeS2 has a high internal resistance, which makes it prone to polarization during the discharge reaction, resulting in a low voltage plateau. Therefore, it cannot meet the high-voltage, stable output requirements of thermal batteries at high temperatures.

[0003] V2O5 is a commonly used oxide cathode material for thermal batteries. However, its high voltage plateau is hindered by its low conductivity, making it difficult to discharge high currents. Copper oxide and cuprous oxide have also been investigated as cathode materials for thermal batteries. However, copper oxide exhibits a shorter first discharge plateau and a longer second discharge plateau, but with a lower voltage. Cuprous oxide exhibits a longer first discharge plateau than copper oxide, but also suffers from slightly lower conductivity. Furthermore, cuprous oxide exhibits poor formability, making the electrode sheet extremely fragile and unsuitable for thermal battery production.

[0004] With the development of miniaturization and intelligence of weapons, high-voltage materials are the current research focus. Based on high-voltage copper oxide materials, flexible electrodes that are not easy to break are prepared. In order to improve the problem of low electrical conductivity, the performance is further improved by coating with carbon-based materials with better conductivity. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a carbon-based coated composite copper oxide flexible electrode material and a preparation method thereof. The carbon-based coated composite copper oxide flexible electrode material is applied to a thermal battery with Li-Si as the negative electrode. The open circuit voltage is 2.5V-2.8V. Under 500°C, 50mA constant current discharge, the first discharge platform is 2.1V-2.3V, there is no obvious voltage spike, the discharge voltage is stable, and when the cut-off voltage is 1.4V, the discharge time is longer than 80min, the duration is long, and it is suitable for long-life thermal batteries. The carbon-based coated composite copper oxide flexible electrode material of the present invention adopts a high-temperature solid-phase method combined with a carbon-based solution self-polymerization reaction. The preparation process is simple, the raw material cost is low, and it has broad application prospects.

[0006] One objective of the present invention is to provide a carbon-based composite copper oxide-coated flexible electrode material, comprising a copper-based material and a carbon-based material coated on the surface of the copper-based material, wherein the copper-based material comprises copper oxide nanowires. The carbon-based composite copper oxide-coated thermal battery positive electrode material comprises dense copper oxide nanowires, with the carbon-based material uniformly grown on the surface.

[0007] In the carbon-based coated composite copper oxide flexible electrode material provided by the present invention:

[0008] The copper oxides include cupric oxide and cuprous oxide;

[0009] The carbon-based material is a polymer of at least one of pyrrole and dopamine;

[0010] The length of the copper oxide nanowires is 0.1 to 50 μm, preferably 1 to 20 μm;

[0011] The particle size of the carbon-based material is 0.1 to 20 nm, preferably 0.5 to 10 nm.

[0012] A second object of the present invention is to provide a method for preparing the above-mentioned carbon-based coated composite copper oxide flexible electrode material, comprising: thermally oxidizing copper foam and placing it in a carbon-based material precursor compound solution, and the carbon-based material precursor compound self-polymerizing on the surface of the copper-based material to obtain the above-mentioned carbon-based coated composite copper oxide flexible electrode material.

[0013] The preparation method of the carbon-based coated composite copper oxide flexible electrode material provided by the present invention specifically comprises the following steps:

[0014] 1) Pressing the copper foam, treating it in an acid solution and then drying it;

[0015] 2) subjecting the dried copper foam to thermal oxidation treatment to obtain a copper-based material;

[0016] 3) placing the copper-based material in a carbon-based material precursor compound solution, causing the carbon-based material precursor compound to undergo a self-polymerization reaction, and then washing and drying to obtain the carbon-based coated composite copper oxide flexible electrode material.

[0017] The present invention provides a method for preparing a carbon-based coated composite copper oxide flexible electrode material, wherein in step 1):

[0018] The porosity of the copper foam is 20 to 500 ppi, preferably 50 to 300 ppi;

[0019] The pressing conditions of the foam copper are: pressure 0.1-5 MPa, time 20-30 seconds; the size of the foam copper material and the pressing thickness are not particularly limited and can be selected according to actual needs;

[0020] The acid in the acid solution is at least one of sulfuric acid, hydrochloric acid, and hydrofluoric acid;

[0021] The molar concentration of the acid in the acid solution is 0.01 to 10 mol / L, preferably 0.05 to 5 mol / L;

[0022] The treatment time in the acid solution is 30 to 60 seconds;

[0023] The copper foam treated with the acid solution is cleaned and then dried. The cleaning step is not particularly limited and can be performed using a common cleaning operation in the prior art, for example, using ultrapure water for cleaning.

[0024] The drying conditions in step 1) are: protective gas atmosphere, temperature 80-100° C., and time 1-10 h, wherein the protective gas can be commonly used nitrogen, argon, etc.

[0025] The method for preparing a carbon-based coated composite copper oxide flexible electrode material provided by the present invention, in step 2):

[0026] The thermal oxidation treatment conditions are: heating to 300-700°C at a heating rate of 2-8°C / min, and the thermal oxidation treatment time is 3-7h;

[0027] The gas atmosphere for the thermal oxidation treatment uses a gas atmosphere with an oxygen volume percentage concentration of 10 to 40%.

[0028] The thermal oxidation treatment can be carried out using a tubular furnace. The copper-based material after pre-treatment is placed in the tubular furnace with a heating rate of 2 to 8°C / min. After reaching the target thermal oxidation temperature, a certain concentration of oxygen mixed gas (such as air, oxygen / air mixed gas, oxygen / nitrogen mixed gas, etc.) is introduced. After the thermal oxidation treatment, the material is cooled to room temperature at a cooling rate of 2 to 8°C / min.

[0029] The method for preparing a carbon-based coated composite copper oxide flexible electrode material provided by the present invention, in step 3):

[0030] The carbon-based material precursor compound is selected from at least one of pyrrole, polypyrrole, dopamine, and polydopamine;

[0031] The solvent of the carbon-based material precursor compound solution is selected from at least one of water, ethanol, and dilute hydrochloric acid; wherein the concentration of the dilute hydrochloric acid has no specific requirement, for example, a molar concentration of 0.01 to 20 mol / L can be used;

[0032] The concentration of the carbon-based material precursor compound in the carbon-based material precursor compound solution is 0.05 to 5 mol / L, preferably 0.1 to 2 mol / L;

[0033] The amount of the carbon-based material precursor compound solution is not particularly limited, as long as it can completely immerse the copper-based material after thermal oxidation treatment;

[0034] The self-polymerization reaction time is 2 to 20 hours, preferably 10 to 15 hours;

[0035] The material obtained after the self-polymerization reaction is first washed and then dried, for example, by rinsing with deionized water for 10 to 20 seconds;

[0036] The drying conditions in step 3) are: temperature 80-90° C., time 8-24 h.

[0037] The present invention prepares a carbon-based coated composite copper oxide thermal battery positive electrode material by a high-temperature solid phase and solution method, and the preparation method preferably includes the following steps:

[0038] 1) Pretreatment of copper-based materials: cleaning impurities on the surface of the foamed copper with an acid solution of the aforementioned concentration, washing the residual acid solution with ultrapure water, and performing oxygen-free drying;

[0039] 2) In-situ thermal oxidation: The pre-treated copper-based material obtained in 1) is placed in a tube furnace, heated to 300-700° C., and introduced into a mixed gas having an oxygen volume concentration of 10%-40% for thermal oxidation treatment, and then cooled to room temperature to obtain a composite copper oxide flexible material;

[0040] 3) In-situ carbon polymerization: The composite copper oxide flexible material after the thermal oxidation in 2) is placed in a 0.1-2 mol / L carbon-based material precursor compound solution and magnetically stirred for 10-15 hours to allow the carbon-based material precursor compound to self-polymerize on the surface of the composite copper oxide; the carbon-based coated composite copper oxide flexible material is removed, rinsed with deionized water for 10-20 seconds, and dried in a drying oven.

[0041] The third object of the present invention is to provide a high-voltage thermal battery cell, comprising a positive electrode material, an electrolyte, a current collector and a negative electrode material, wherein the negative electrode material is at least one of lithium alloy powders, the current collector is a nickel sheet, the electrolyte is a lithium salt, and the positive electrode material is the carbon-based coated composite copper oxide flexible electrode material described in one of the objects of the present invention or the carbon-based coated composite copper oxide flexible electrode material obtained by the preparation method described in the second object of the present invention; preferably,

[0042] The negative electrode material is selected from at least one of lithium silicon alloy powder and lithium boron alloy powder;

[0043] The electrolyte is at least one of a solid LiF-LiCl-LiBr ternary full lithium electrolyte and a solid LiF-LiCl-KCl ternary electrolyte;

[0044] The thickness of the current collecting sheet is 0.01 to 2 mm, preferably 0.1 to 1 mm.

[0045] A fourth object of the present invention is to provide a method for preparing the above-mentioned high-voltage thermal battery single cell, comprising: in a protective gas atmosphere, sequentially adding a negative electrode material, an electrolyte, and a positive electrode material into a mold, pressing them into a cylindrical sheet, and placing current collectors on both sides of the positive and negative electrodes of the cylindrical sheet to obtain the above-mentioned high-voltage thermal battery single cell.

[0046] In the method for preparing a high-voltage thermal battery cell provided by the present invention:

[0047] The protective gas is not particularly limited, and commonly used protective gases such as nitrogen, argon, etc. can be used;

[0048] The mass ratio of the negative electrode material, the electrolyte, and the positive electrode material is 1: (1.5-2): (1-1.5), preferably 1: (1.5-1.8): (1-1.3);

[0049] The pressing conditions are: pressure of 12 to 16 MPa and holding time of 10 to 20 seconds.

[0050] Beneficial effects of the present invention:

[0051] (1) The carbon-based coated composite copper oxide flexible electrode material prepared by the present invention is based on high-voltage nano-copper oxide material and porous foam copper as a flexible substrate. The performance is further improved by coating the carbon-based material with good conductivity. Its voltage and specific capacity are higher than those of the unoptimized powder copper oxide material.

[0052] (2) The present invention adopts a high-temperature solid-phase method to obtain the positive electrode material. The size, shape, and quality of the electrode sheet can be changed according to actual requirements. The prepared material has high purity and a complete crystal structure, which improves its electrochemical performance as a thermoelectric battery electrode material.

[0053] (3) The present invention eliminates the need for secondary powder compaction during the preparation of high-voltage, long-life thermal battery cells. The thermal battery cells have distinct edges and are less susceptible to short circuits. The applied pressure is 12-16 MPa, allowing for integrated molding and easy operation.

[0054] (4) The thermal battery cell prepared from the carbon-based coated composite copper oxide flexible electrode material provided by the present invention has no obvious voltage spikes, and the constant current discharge voltage is stable and the time is long. Therefore, the carbon-based coated composite copper oxide flexible electrode material of the present invention is suitable for high-voltage and long-life thermal batteries.

[0055] (5) The carbon-based coated composite copper oxide flexible electrode material prepared by the present invention adopts a combination of high-temperature solid-phase method and solution method. The preparation process is simple, the raw materials are easily available, the cost is low, the repeatability is high, and it has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is the X-ray diffraction (XRD) pattern of the carbon-based coated composite copper oxide flexible electrode material of Example 1, a is the spectrum of the carbon-based coated composite copper oxide flexible electrode material of Example 1, b is the spectrum of the Cu2O standard card, c is the spectrum of the CuO standard card, and d is the spectrum of the Cu standard card.

[0057] Figure 2 This is a scanning electron microscope (SEM) image of the copper-based material after thermal oxidation in Example 1.

[0058] Figure 3 This is a scanning electron microscope (SEM) image of the carbon-based coated composite copper oxide flexible electrode material of Example 1.

[0059] Figure 4 A comparison of the constant current discharge curves at 50 mA at 500°C for a thermal battery prepared using the carbon-based coated composite copper oxide flexible electrode material prepared in Example 1 of the present invention as the positive electrode material of a thermal battery and the thermal batteries prepared using the copper oxide powder material (CuO) in Comparative Example 1 and the cuprous oxide powder material (Cu2O) in Comparative Example 2 as the positive electrode material of a thermal battery is shown. Curve a in the figure represents the constant current discharge curve of the thermal battery prepared using the carbon-based coated composite copper oxide flexible electrode as the positive electrode material of the thermal battery in Example 1, curve b in the figure represents the constant current discharge curve of the thermal battery prepared using the cuprous oxide material (Cu2O) as the positive electrode material of the thermal battery in Comparative Example 2, and curve c in the figure represents the constant current discharge curve of the thermal battery prepared using the copper oxide material (CuO) as the positive electrode material of the thermal battery in Comparative Example 1. DETAILED DESCRIPTION

[0060] The present invention will be described in detail below with reference to specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art to the present invention based on the contents of the present invention still fall within the scope of protection of the present invention.

[0061] The test instruments and test conditions used in the examples are as follows:

[0062] The X-ray diffraction pattern of the carbon-based coated composite copper oxide flexible electrode material of the present invention is obtained by testing using a Bruker D2 X-ray diffractometer;

[0063] The scanning electron microscope images of the present invention were obtained by testing using a Phenom ProX scanning electron microscope;

[0064] The discharge performance test in the embodiment of the present invention was performed using an Autolab PGSTAT 302N electrochemical workstation.

[0065] Unless otherwise specified, the raw materials used in the examples and comparative examples are all disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0066] Example 1

[0067] Preparation of carbon-based coated composite copper oxide flexible electrode materials:

[0068] A 300ppi porosity copper foam was selected and cut into the size of a circular electrode sheet (18mm in diameter). The copper foam electrode sheet was then pressed under a pressure of 5MPa for 20s. The pressed copper foam was placed in a 0.1mol / L dilute hydrochloric acid pretreatment solution, ultrasonically cleaned for 50s, then rinsed with ultrapure water and dried at 90°C under a nitrogen atmosphere for 1h. The pretreated copper-based material was placed in a tube furnace with a heating rate of 5°C / min, a target temperature of 600°C, and a 10% volume percent oxygen / nitrogen mixed gas. The material was thermally oxidized for 5h, cooled at 5°C / min, and removed from the furnace after cooling to room temperature to obtain a composite copper oxide flexible material. The composite copper oxide flexible material was placed in 50 mL of a 1 mol / L dopamine hydrochloride aqueous solution and magnetically stirred for 15 hours to allow the carbon-based material to self-polymerize on the surface of the composite copper oxide; the carbon-based coated composite copper oxide flexible material was taken out, rinsed with deionized water for 20 seconds, and placed in a drying oven at 80°C for 12 hours to obtain a carbon-based coated composite copper oxide flexible electrode material.

[0069] The X-ray diffraction (XRD) pattern of the carbon-based coated composite copper oxide flexible electrode material of Example 1 is as follows: Figure 1 As shown, from Figure 1 It can be seen that the material crystal form of the carbon-based coated composite copper oxide flexible electrode material prepared in Example 1 has a high degree of match with the CuO, Cu2O, and Cu standard cards, and the crystal form is complete, indicating that two composite copper-based oxide materials have been successfully prepared.

[0070] The scanning electron microscope (SEM) image of the carbon-based composite copper oxide flexible electrode material of Example 1 is as follows: Figure 3 As shown, from Figure 3 The carbon-based composite copper oxide flexible electrode material has distinct needle-like nanowires, and the coated carbon-based material particles are uniform. The copper oxide nanowires are 5 to 15 μm long, and the carbon-based material particles are 1 to 3 nm in size.

[0071] Preparation of thermal battery cells:

[0072] In this embodiment, lithium silicon alloy powder is used as the negative electrode, solid LiF-LiCl-LiBr ternary all-lithium electrolyte, carbon-based coated composite copper oxide flexible electrode material is used as the positive electrode material, and two nickel current collectors are used to form a high voltage and long life thermal battery cell. A stainless steel cylindrical mold was added to the mold in sequence under argon protection in a glove box. A pressure of 13 MPa was applied, and the mold was removed after holding for 15 seconds. A nickel current collector was placed on both sides of the positive and negative electrodes of the pressed cylinder to obtain a high-voltage and long-life thermal battery cell 1. The cell was discharged at a constant current of 50 mA at 500°C, with an open circuit voltage of 2.7 V, a first discharge platform of 2.2 V to 2.3 V, and a discharge time of more than 80 minutes when the cut-off voltage was 1.4 V.

[0073] Example 2

[0074] Preparation of carbon-based coated composite copper oxide flexible electrode materials:

[0075] A 200ppi porosity copper foam was selected and cut into the size of a circular electrode sheet (16mm in diameter). The copper foam electrode sheet was then pressed with a pressure of 4MPa for 30s. The pressed copper foam was placed in a 0.1mol / L dilute sulfuric acid pretreatment solution, ultrasonically cleaned for 50s, then rinsed with ultrapure water and dried at 80°C under a nitrogen atmosphere for 2h. The pretreated copper-based material was placed in a tube furnace with a heating rate of 5°C / min, a target temperature of 500°C, and a 15% volume percent oxygen / nitrogen mixture introduced for thermal oxidation treatment for 4h. The material was then cooled to room temperature at a rate of 6°C / min and removed. The composite copper oxide flexible material was placed in 60 mL of a 1.5 mol / L polypyrrole-0.1 mol / L dilute hydrochloric acid solution and magnetically stirred for 12 hours to allow the carbon-based material to self-polymerize on the surface of the composite copper oxide. The carbon-based-coated composite copper oxide flexible material was removed, rinsed with deionized water for 20 seconds, and dried in a drying oven at 85°C for 14 hours to obtain a carbon-based-coated composite copper oxide flexible electrode material. The resulting copper oxide nanowires were 2 to 13 μm in length, and the carbon-based material particles were 2 to 6 nm in diameter.

[0076] Preparation of thermal battery cells:

[0077] A high-voltage, long-life thermal battery single cell was constructed using lithium-silicon alloy powder as the negative electrode, a solid LiF-LiCl-LiBr ternary all-lithium electrolyte, a carbon-based composite copper oxide flexible electrode material as the positive electrode material, and two nickel current collectors. In a glove box, under argon protection, 0.2g of the negative electrode, 0.35g of the electrolyte, and 0.25g of the positive electrode material were sequentially added to a mold (the same mold as in Example 1). A pressure of 14 MPa was applied, and the mold was removed after a 20-second dwell. A nickel current collector was placed on each side of the positive and negative electrodes of the pressed cylindrical structure to produce a high-voltage, long-life thermal battery single cell 2. This single cell was discharged at a constant current of 50 mA at 500°C, with an open circuit voltage of 2.6V, a first discharge plateau of 2.1V-2.3V, and a discharge duration of more than 70 minutes at a cutoff voltage of 1.5V.

[0078] Example 3

[0079] Preparation of carbon-based coated composite copper oxide flexible electrode materials:

[0080] A 100ppi porosity copper foam was cut into circular electrode pieces (17mm in diameter) and then pressed at 3MPa for 30s. The pressed copper foam was then placed in a pretreatment solution of 0.1mol / L dilute hydrochloric acid, ultrasonically cleaned for 50s, rinsed with ultrapure water, and dried at 90°C under an argon atmosphere for 2h. The resulting pretreated copper-based material was placed in a tube furnace and heated at a rate of 5°C / min to a target temperature of 500°C. A 10% volume percent oxygen / nitrogen mixture was introduced for thermal oxidation for 6h, followed by a cooling rate of 4°C / min. The composite copper oxide flexible material was then placed in 40mL of a 0.5mol / L dopamine hydrochloride ethanol solution and magnetically stirred for 12h to allow the carbon-based material to self-polymerize on the surface of the composite copper oxide. The carbon-coated composite copper oxide flexible material was removed, rinsed with deionized water for 20s, and dried in a drying oven at 90°C for 15h to obtain a carbon-coated composite copper oxide flexible electrode material. In the obtained carbon-based coated composite copper oxide flexible electrode material, the length of the copper oxide nanowire is 1 to 12 μm, and the particle size of the carbon-based material is 3 to 7 nm.

[0081] Preparation of thermal battery cells:

[0082] A high-voltage, long-life thermal battery single cell was composed of lithium-silicon alloy powder as the negative electrode, a solid LiF-LiCl-LiBr ternary all-lithium electrolyte, a carbon-based coated composite copper oxide flexible electrode material as the positive electrode material, and two nickel current collectors. In an argon atmosphere, 0.2 g of the negative electrode, 0.35 g of the electrolyte, and 0.22 g of the positive electrode material were sequentially added to a mold (the mold was the same as in Example 1). A pressure of 14 MPa was applied, and the mold was removed after 15 seconds. A nickel current collector was placed on both sides of the positive and negative electrodes of the cylinder obtained by pressing to obtain a high-voltage, long-life thermal battery single cell 3. The single cell was discharged at a constant current of 50 mA at 500°C, with an open circuit voltage of 2.71 V, a first discharge platform of 2.2 V-2.3 V, and a discharge time of more than 75 min when the cut-off voltage was 1.4 V.

[0083] Comparative Example 1

[0084] A thermal battery cell is composed of lithium silicon alloy powder as the negative electrode, solid LiF-LiCl-LiBr ternary full lithium electrolyte (the same solid LiF-LiCl-LiBr ternary full lithium electrolyte used in Example 1), copper oxide powder material (CuO), and two nickel current collectors. A stainless steel cylindrical mold was used. 0.2 g of negative electrode, 0.35 g of electrolyte, and 0.2 g of positive electrode material were added to the mold in sequence under the argon atmosphere of a glove box. A pressure of 13 MPa was applied and the mold was removed after 15 seconds. A nickel current collector was placed on both sides of the positive and negative electrodes of the pressed single battery and a discharge test was performed. The battery was discharged at a constant current of 50 mA at 500°C. The discharge platforms were 2.1 V and 1.7 V. When the cut-off voltage was 1.4 V, the discharge time was 70 min.

[0085] Comparative Example 2

[0086] The same procedures as in Comparative Example 1 were followed, except that cuprous oxide powder (Cu2O) was used instead of copper oxide powder (CuO). The resulting battery was subjected to a discharge test. At 500°C and a constant current of 50 mA, the battery exhibited discharge plateaus of 2.2 V and 1.95 V, with voltage spikes present. The cutoff voltage reached 1.4 V, and the discharge duration was 71 minutes.

[0087] The thermal battery prepared by using the carbon-based coated composite copper oxide flexible electrode material prepared in Example 1 of the present invention as the positive electrode material of the thermal battery and the thermal battery prepared by using the copper oxide powder material (CuO) or cuprous oxide powder material (Cu2O) as the positive electrode material of the thermal battery in Comparative Example 1 are shown in the following figure: Figure 4 As shown, from Figure 4It can be seen that the voltage platform (2.2V) of the thermal battery prepared with the carbon-based coated composite copper oxide flexible electrode material as the positive electrode material of the thermal battery is significantly higher than the voltage platform of the thermal battery prepared with copper oxide powder material (CuO) and cuprous oxide powder material (Cu2O) as the positive electrode material of the thermal battery. The discharge time is also longer, which meets the requirements of high-voltage thermal battery positive electrode materials.

[0088] It can be seen from the embodiments and comparative examples that the constant current discharge voltage of the thermal battery single cell prepared by the carbon-based coated composite copper oxide flexible electrode material of the present invention is stable and the time is long. Compared with conventional powdered copper oxide materials, the carbon-based coated composite copper oxide flexible electrode material of the present invention is more suitable as a positive electrode material for high-voltage and long-life thermal batteries.

[0089] While the embodiments of the present invention have been described above, the above description is intended to be exemplary, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A carbon-based coated composite copper oxide flexible electrode material comprising: A copper-based material and a carbon-based material coated on the surface of the copper-based material, wherein the copper-based material comprises copper oxide nanowires.

2. The carbon-based coated composite copper oxide flexible electrode material according to claim 1, characterized in that: The copper oxides include cupric oxide and cuprous oxide; and / or, The carbon-based material is a polymer of at least one of pyrrole and dopamine; and / or, The length of the copper oxide nanowires is 0.1 to 50 μm, preferably 1 to 20 μm; and / or, The particle size of the carbon-based material is 0.1 to 20 nm, preferably 0.5 to 10 nm.

3. A method for preparing the carbon-based coated composite copper oxide flexible electrode material according to any one of claims 1 to 2, comprising: The foamed copper is placed in a carbon-based material precursor compound solution after thermal oxidation, and the carbon-based material precursor compound self-polymerizes on the surface of the copper-based material to obtain the carbon-based coated composite copper oxide flexible electrode material.

4. The preparation method according to claim 3, characterized in that The preparation method specifically comprises the following steps: 1) Pressing the copper foam, treating it in an acid solution and then drying it; 2) subjecting the dried copper foam to thermal oxidation treatment to obtain a copper-based material; 3) placing the copper-based material in a carbon-based material precursor compound solution, causing the carbon-based material precursor compound to undergo a self-polymerization reaction, and then washing and drying to obtain the carbon-based coated composite copper oxide flexible electrode material.

5. The preparation method according to claim 4, characterized in that In the step 1): The pressing conditions of the foam copper are: pressure 0.1-5 MPa, pressing time 20-30 s; and / or, The porosity of the copper foam is 20 to 500 ppi, preferably 50 to 300 ppi; and / or, The acid in the acid solution is at least one of sulfuric acid, hydrochloric acid, and hydrofluoric acid; and / or, The molar concentration of the acid in the acid solution is 0.01 to 10 mol / L, preferably 0.05 to 5 mol / L; and / or, The treatment time in the acid solution is 30 to 60 seconds; and / or, The drying conditions in step 1) are: protective gas atmosphere, temperature 80-100° C., and time 1-10 h.

6. The preparation method according to claim 4, characterized in that In the step 2): The thermal oxidation treatment conditions are: heating to 300-700°C at a heating rate of 2-8°C / min, and the thermal oxidation treatment time is 3-7h; and / or, The gas atmosphere of the thermal oxidation treatment adopts a gas atmosphere with an oxygen volume percentage concentration of 10 to 40%; and / or, After the thermal oxidation treatment is completed, the temperature is lowered at a rate of 2 to 8° C. / min.

7. The preparation method according to claim 4, characterized in that In the step 3): The carbon-based material precursor compound is selected from at least one of pyrrole, polypyrrole, dopamine, and polydopamine; and / or, The solvent of the carbon-based material precursor compound solution is selected from at least one of water, ethanol, and dilute hydrochloric acid; and / or, The concentration of the carbon-based material precursor compound in the carbon-based material precursor compound solution is 0.05 to 5 mol / L, preferably 0.1 to 2 mol / L; and / or, The self-polymerization reaction time is 2 to 20 hours, preferably 10 to 15 hours; and / or, The drying conditions in step 3) are: temperature 80-90° C., time 8-24 h.

8. A high-voltage thermal battery cell, comprising a positive electrode material, an electrolyte, a current collector, and a negative electrode material, wherein the negative electrode material is at least one of lithium alloy powders, the current collector is a nickel sheet, the electrolyte is a lithium salt, and the positive electrode material is the carbon-based coated composite copper oxide flexible electrode material according to any one of claims 1 to 2 or the carbon-based coated composite copper oxide flexible electrode material prepared by the method according to any one of claims 3 to 7; preferably, The negative electrode material is selected from at least one of lithium silicon alloy powder and lithium boron alloy powder; and / or, The electrolyte is at least one of a solid LiF-LiCl-LiBr ternary all-lithium electrolyte and a solid LiF-LiCl-KCl ternary electrolyte; and / or, The thickness of the current collecting sheet is 0.01 to 2 mm, preferably 0.1 to 1 mm.

9. A method for preparing the high-voltage thermal battery cell according to claim 8, comprising: Under a protective gas atmosphere, negative electrode material, electrolyte, and positive electrode material are sequentially added to a mold and pressed into a cylindrical sheet. Current collectors are placed on both sides of the positive and negative electrodes of the cylindrical sheet to obtain the high-voltage thermal battery cell.

10. The preparation method according to claim 9, characterized in that The mass ratio of the negative electrode material, the electrolyte, and the positive electrode material is 1:(1.5-2):(1-1.5), preferably 1:(1.5-1.8):(1-1.3); and / or, The pressing conditions are: pressure of 12 to 16 MPa and holding time of 10 to 20 seconds.

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