Lightweight thermal battery and preparation method thereof

Abstract

The invention provides a lightweight thermal battery and a preparation method thereof. The cobalt sulfide electrode material is prepared by taking the stainless steel felt as the substrate and adopting an electropolymerization method, so that the problem of relatively low conductivity of the material can be improved, meanwhile, a light-weight thermal battery is assembled, and further improvement of performance and diversification of application scenes are realized.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal battery electrode materials, and in particular relates to a lightweight thermal battery and a preparation method thereof. Background Art

[0002] Thermal batteries, also known as heat-activated reserve batteries, are disposable lithium batteries that use an electric spark to ignite an internal heating agent to instantly heat up and melt the solid electrolyte. They have the following characteristics: In the unactivated state, the electrolyte is solid and non-conductive, so the battery remains insulated, thereby effectively preventing self-discharge and achieving long-term storage without energy decay. Thermal batteries are particularly suitable for military equipment and other occasions that require instantaneous high-power discharge due to their high energy density, high power output and excellent stability.

[0003] At present, the most commonly used positive electrode materials in thermal batteries are transition metal sulfides and oxides. Among them, CoS2 has become the most commonly used positive electrode material in thermal batteries due to its simple preparation and stable voltage. However, CoS2 is prone to polarization during the discharge reaction, with a low voltage platform and low specific capacity, so it cannot meet the working requirements of thermal batteries for high voltage stable output at high temperatures. Summary of the invention

[0004] With the development of miniaturization and intelligence of weapons, the current research focus of thermal batteries is on the development of new positive electrode materials and preparation methods. Using stainless steel felt as a substrate and preparing cobalt sulfide electrode materials by electropolymerization can improve the problem of low material conductivity. At the same time, lightweight thermal batteries can be assembled to achieve further performance improvement and diversification of application scenarios.

[0005] One of the purposes of the present invention is to provide a lightweight thermal battery, comprising: a cobalt sulfide electrode material as a positive electrode material, a lithium silicon alloy as a negative electrode material, an inorganic lithium salt as an electrolyte, and a current collector.

[0006] According to the present invention, in the lightweight thermal battery:

[0007] The amount of the positive electrode material and the negative electrode material can be adjusted according to the commonly used amount. For example, the mass ratio of the positive electrode material to the negative electrode material is 1:(1-4), for example, it can be any ratio of 1:1, 1:2, 1:3, 1:4 or a numerical ratio between any two numerical ranges mentioned above. Preferably, the mass ratio of the positive electrode material to the negative electrode material is 1:(1.2-3.5);

[0008] The amount of the negative electrode material and the electrolyte can be adjusted according to the commonly used amounts. For example, the mass ratio of the negative electrode material to the electrolyte is 1:(1.5-2.2). For example, it can be any ratio of 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:2.1, 1:2.2 or a numerical ratio between any two of the above numerical ranges. Preferably, the mass ratio of the negative electrode material to the electrolyte is 1:(1-2).

[0009] According to the present invention, in the lightweight thermal battery:

[0010] The inorganic lithium salt comprises lithium fluoride, lithium chloride and lithium bromide; the dosage of the lithium fluoride, lithium chloride and lithium bromide can be adjusted according to the commonly used dosage, for example, the mass ratio of the lithium fluoride, lithium chloride and lithium bromide is 1: (2.0-2.5): (7.0-7.5), preferably, the mass ratio of the lithium fluoride, lithium chloride and lithium bromide is 1: (2.3-2.4): (7.1-7.2), more preferably, the mass ratio of the lithium fluoride, lithium chloride and lithium bromide is 1: (2.30-2.35): (7.15-7.20).

[0011] According to the present invention, the current collecting sheet of the lightweight thermal battery can be made of commonly used current collecting sheet materials. For example, the current collecting sheet is selected from one of stainless steel and nickel.

[0012] According to the present invention, the cobalt sulfide electrode material comprises a stainless steel felt substrate and cobalt sulfide;

[0013] Preferably, the cobalt sulfide is electrodeposited on a stainless steel felt substrate using cyclic voltammetry;

[0014] More preferably, the content of cobalt sulfide in the cobalt sulfide electrode material is 70-90wt%, for example, it can be any value among 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90wt% or a value between any two of the above numerical ranges. Further preferably, the content of cobalt sulfide in the cobalt sulfide electrode material is 80-90wt%.

[0015] According to an embodiment of the present invention, the cobalt sulfide electrode material is prepared by the following steps:

[0016] (1) adding a soluble cobalt salt and thiourea into water to obtain a mixed aqueous solution;

[0017] (2) Using the mixed aqueous solution obtained in step (1) as an electrolyte and stainless steel felt as a substrate, cyclic voltammetry is used to electrodeposit cobalt sulfide to obtain the cobalt sulfide electrode material.

[0018] Specifically, in step (1):

[0019] The soluble cobalt salt may be a commonly used soluble inorganic salt, for example, the soluble cobalt salt is selected from at least one of cobalt chloride and cobalt nitrate;

[0020] The molar ratio of the soluble cobalt salt to thiourea is 1:(15-30), for example, it can be any value among 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, 1:21, 1:22, 1:23, 1:24, 1:25, 1:26, 1:27, 1:28, 1:29, 1:30 or a value between any two of the above numerical ranges; preferably, the molar ratio of the soluble cobalt salt to thiourea is 1:(20-25);

[0021] In the mixed aqueous solution, the concentration of the soluble cobalt salt is 0.5-0.7 mol / L, for example, it can be any value among 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.7 mol / L or a value between any two of the above numerical ranges. Preferably, in the mixed aqueous solution, the concentration of the soluble cobalt salt is 0.6-0.65 mol / L;

[0022] In the step (2):

[0023] The thickness of the stainless steel felt is 0.3-0.6 μm, for example, any value among 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6 μm or a thickness value between any two of the above value ranges. Preferably, the thickness of the stainless steel felt is 0.4-0.45 μm;

[0024] The conditions of the electrodeposition are: a potential interval of 1.2 to 0.2 V, a scan rate of 4 to 6 mV / s, and a scan number of 5 to 15;

[0025] The electrodeposition is followed by a cleaning and drying step; the cleaning may be performed using a commonly used cleaning solvent, for example, the cleaning solvent is selected from at least one of anhydrous ethanol and deionized water; the drying may be performed using conventional drying equipment and drying conditions, for example, the drying condition is 60-70°C.

[0026] The second object of the present invention is to provide a method for preparing the above-mentioned lightweight thermal battery, comprising: sequentially adding negative electrode material, electrolyte, and positive electrode material into a mold for compression molding, and placing current collectors on both sides of the positive and negative electrodes after demolding to obtain the lightweight thermal battery.

[0027] According to the present invention, the conditions for compression molding in the method for preparing the lightweight thermal battery are: pressure 12 to 16 MPa, and residence time 20 to 30 s.

[0028] The technical solution provided by the present invention has the following beneficial effects:

[0029] (1) Improve electrode material properties

[0030] Traditional cobalt sulfide materials have low electrical conductivity, which limits their performance in batteries. However, through the electropolymerization method, cobalt sulfide is deposited on a stainless steel felt substrate. The stainless steel felt itself has good electrical conductivity, which can effectively improve the electrical conductivity of the entire electrode material and make the transmission of electrons in the electrode material smoother, thereby improving the discharge performance of the battery, reducing polarization, and improving the stability of the voltage platform.

[0031] (2) Accelerate electrochemical reactions

[0032] The improvement of conductivity helps to accelerate the electrochemical reaction rate between the electrode material and the electrolyte. During the battery discharge process, the electrode material can react more quickly with the ions in the electrolyte, releasing more electrical energy and improving the battery's specific capacity and power density.

[0033] (3) Base support

[0034] Stainless steel felt serves as a substrate, providing a solid support structure for cobalt sulfide. During the battery discharge process, it can effectively alleviate the damage to the electrode material structure caused by the insertion and removal of these ions, maintain the integrity of the electrode material, and extend the battery discharge time. During the electropolymerization process, the bonding force between cobalt sulfide and stainless steel felt is strong, allowing cobalt sulfide to be firmly attached to the substrate and not easily fall off, thus avoiding battery performance degradation or failure due to the fall-off of electrode materials.

[0035] (4) Good repeatability

[0036] The electropolymerization process is carried out under the precise control of equipment such as an electrochemical workstation, which can ensure that the cobalt sulfide electrode material prepared each time has high repeatability and consistency. This is conducive to the large-scale production and quality control of batteries, and improves the performance stability and reliability of battery products.

[0037] (5) Meeting lightweight requirements

[0038] The cobalt sulfide electrode material prepared by the electropolymerization method can achieve lightweight electrode materials while ensuring performance. This is of great significance for some application scenarios that have strict requirements on weight, such as aerospace, military equipment and other fields. Lightweight thermal batteries can reduce the burden on equipment, improve the mobility and flexibility of equipment, while meeting its needs for high energy density and high power output.

[0039] (6) Adapting to high-performance battery requirements

[0040] With the continuous development of science and technology, the requirements for battery performance are getting higher and higher. The cobalt sulfide electrode materials prepared by the electropolymerization method have the advantages of high conductivity and good structural stability, which enable them to better meet the needs of high-performance batteries, such as long life, high specific capacity, high power density, etc., thereby expanding the application prospects of thermal batteries in electronic equipment under special environments, large-scale energy storage and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is the XRD of the cobalt sulfide electrode material prepared in Example 1.

[0042] Figure 2 This is the SEM of the cobalt sulfide electrode material prepared in Example 1.

[0043] Figure 3 ] are the discharge curves of the lightweight thermal batteries prepared in Examples 1 to 3, wherein a is the discharge curve of the lightweight thermal battery obtained in Example 1, b is the discharge curve of the lightweight thermal battery obtained in Example 3, and c is the discharge curve of the lightweight thermal battery obtained in Example 2.

[0044] Figure 4 ] are the discharge curves of the lightweight thermal batteries prepared in Example 1 and Comparative Examples 1-2, wherein a is the discharge curve of the lightweight thermal battery obtained in Example 1, b is the discharge curve of the lightweight thermal battery obtained in Comparative Example 1, and c is the discharge curve of the lightweight thermal battery obtained in Comparative Example 2. DETAILED DESCRIPTION

[0045] The invention provides a lightweight thermal battery, comprising: a cobalt sulfide electrode material as a positive electrode material, a lithium silicon alloy as a negative electrode material, an inorganic lithium salt as an electrolyte, and a current collector.

[0046] Wherein, the cobalt sulfide electrode material comprises a stainless steel felt substrate and cobalt sulfide;

[0047] Preferably, the cobalt sulfide is electrodeposited on a stainless steel felt substrate using cyclic voltammetry;

[0048] More preferably, the content of cobalt sulfide in the cobalt sulfide electrode material is 70 to 90 wt%;

[0049] Further preferably, in the cobalt sulfide electrode material, the content of cobalt sulfide is 80-90 wt%.

[0050] According to a specific embodiment of the present invention, the cobalt sulfide electrode material is prepared by the following steps:

[0051] (1) adding a soluble cobalt salt and thiourea into water to obtain a mixed aqueous solution;

[0052] (2) Using the mixed aqueous solution obtained in step (1) as an electrolyte and stainless steel felt as a substrate, cyclic voltammetry is used to electrodeposit cobalt sulfide to obtain the cobalt sulfide electrode material.

[0053] Specifically, in step (1):

[0054] The soluble cobalt salt may be a commonly used soluble inorganic salt, for example, the soluble cobalt salt is selected from at least one of cobalt chloride and cobalt nitrate;

[0055] The molar ratio of the soluble cobalt salt to thiourea is 1:(15-30), preferably, the molar ratio of the soluble cobalt salt to thiourea is 1:(20-25);

[0056] In the mixed aqueous solution, the concentration of the soluble cobalt salt is 0.5 to 0.7 mol / L. Preferably, in the mixed aqueous solution, the concentration of the soluble cobalt salt is 0.6 to 0.65 mol / L.

[0057] In the step (2):

[0058] The thickness of the stainless steel felt is 0.3-0.6 μm, preferably, the thickness of the stainless steel felt is 0.4-0.45 μm;

[0059] The conditions of the electrodeposition are: a potential interval of 1.2 to 0.2 V, a scan rate of 4 to 6 mV / s, and a scan number of 5 to 15;

[0060] The electrodeposition is followed by a cleaning and drying step; the cleaning may be performed using a commonly used cleaning solvent, for example, the cleaning solvent is selected from at least one of anhydrous ethanol and deionized water; the drying may be performed using conventional drying equipment and drying conditions, for example, the drying condition is 60-70°C.

[0061] According to a specific embodiment of the present invention, in the lightweight thermal battery:

[0062] The amount of the positive electrode material and the negative electrode material can be adjusted according to the commonly used amount. For example, the mass ratio of the positive electrode material to the negative electrode material is 1:(1-4). Preferably, the mass ratio of the positive electrode material to the negative electrode material is 1:(1.2-3.5);

[0063] The amount of the negative electrode material and the electrolyte can be adjusted according to the commonly used amount. For example, the mass ratio of the negative electrode material to the electrolyte is 1:(1.5-2.2). Preferably, the mass ratio of the negative electrode material to the electrolyte is 1:(1-2).

[0064] According to a specific embodiment of the present invention, in the lightweight thermal battery:

[0065] The inorganic lithium salt comprises lithium fluoride, lithium chloride and lithium bromide; the amounts of the lithium fluoride, lithium chloride and lithium bromide can be adjusted according to the commonly used amounts. Preferably, the mass ratio of the lithium fluoride, lithium chloride and lithium bromide is 1:(2.3-2.4):(7.1-7.2), and more preferably, the mass ratio of the lithium fluoride, lithium chloride and lithium bromide is 1:(2.30-2.35):(7.15-7.20).

[0066] According to a specific embodiment of the present invention, the current collecting sheet of the lightweight thermal battery can be made of commonly used current collecting sheet materials. For example, the current collecting sheet is selected from one of stainless steel and nickel.

[0067] The present invention also provides a method for preparing the above-mentioned lightweight thermal battery, comprising: sequentially adding negative electrode material, electrolyte, and positive electrode material into a mold for compression molding, and placing current collectors on both sides of the positive and negative electrodes after demolding to obtain the lightweight thermal battery.

[0068] According to a specific embodiment of the present invention, the conditions for compression molding in the preparation method of the lightweight thermal battery are: pressure 12 to 16 MPa, and residence time 20 to 30 s.

[0069] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0070] The test instruments and test conditions used in the examples are as follows:

[0071] Discharge curve test method:

[0072] The electrochemical performance of the thermal battery was studied using an Autolab electrochemical workstation (Metrohm, PGSTAT302N, Switzerland) connected to an argon-filled tube furnace (ROTH 75 / 200 / 18, Germany). The assembled battery was placed in the tube furnace and placed at 500 °C for 20 min before each measurement. The constant current discharge test was measured at 250 mA / g.

[0073] The raw materials used in the examples and comparative examples, unless otherwise specified, are disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0074] Example 1

[0075] Preparation of cobalt sulfide (CoS) electrode material:

[0076] A stainless steel felt with a thickness of 0.4 μm was used as the substrate, and the solution was a mixed aqueous solution of 0.05 M CoCl2·6H2O and 1.0 M thiourea. Cyclic voltammetry (CV) was used for electropolymerization through an electrochemical workstation, with the potential interval set between 1.2 V and 0.2 V, a scan rate of 5 mV / s, and a scan number of 6 cycles. After electrodeposition, the sample was washed three times with ethanol and distilled water, and then dried in a vacuum drying oven at 60 ° C to obtain the CoS electrode material.

[0077] Preparation of lightweight thermal battery:

[0078] A high-voltage, lightweight, long-life thermal battery cell is composed of lithium-silicon alloy powder as the negative electrode, a solid LiF-LiCl-LiBr ternary all-lithium electrolyte (the mass ratio of lithium fluoride, lithium chloride and lithium bromide is 1:2.3:7.15), the above-mentioned electropolymerization prepared cobalt sulfide flexible electrode material as the positive electrode material, and two current collectors.

[0079] Using a φ16 stainless steel cylindrical mold, add 0.1g of negative electrode, 0.2g of electrolyte and 0.05g of positive electrode material (the CoS electrode material prepared above) to the mold in turn under argon protection in a glove box, apply 14MPa pressure, stay for 20s and then remove the mold. Place a nickel current collector on both sides of the positive and negative electrodes of the pressed cylinder to obtain a high-voltage, long-life lightweight thermal battery. After testing, the lightweight thermal battery was discharged at a constant current of 250mA / g at 500℃, with an open circuit voltage of 2.33V and a discharge capacity of more than 337mAh / g when the cut-off voltage was 1.3V.

[0080] The electrode material, ternary all-lithium electrolyte and lithium-silicon alloy negative electrode form a single lightweight thermal battery. Under 500°C, 250mA / g constant current discharge, there is no obvious voltage spike, the discharge voltage is stable, and when the cut-off voltage is 1.3V, the discharge capacity exceeds 337mAh / g, with a long duration, which is suitable for long-life lightweight thermal batteries. Stainless steel electrodes are relatively stable and have a certain degree of flexibility, which is suitable for the application of high-voltage long-life thermal batteries in extreme environments.

[0081] Example 2

[0082] The preparation process of Example 1 was adopted, except that the positive electrode material was 0.075 g. Specifically:

[0083] A φ16 stainless steel cylindrical mold was used, and 0.1 g of a negative electrode (lithium silicon alloy powder), 0.2 g of an electrolyte (solid LiF-LiCl-LiBr ternary all-lithium electrolyte, the same as in Example 1) and 0.075 g of a positive electrode material (the CoS electrode material prepared in Example 1) were added to the mold in sequence under argon protection in a glove box. A pressure of 14 MPa was applied, and the mold was removed after staying for 20 seconds. A nickel current collector was placed on both sides of the positive and negative electrodes of the cylinder obtained by compression molding to obtain a high-voltage, long-life, lightweight thermal battery.

[0084] After testing, the lightweight thermal battery was discharged at a constant current of 250mA / g at 500°C, with an open circuit voltage of 2.28V and a cut-off voltage of 1.3V, and the discharge capacity was about 285mAh / g.

[0085] Example 3

[0086] The preparation process of Example 1 was adopted, except that the positive electrode material was 0.03 g. Specifically:

[0087] A φ16 stainless steel cylindrical mold was used, and 0.1 g of a negative electrode (lithium silicon alloy powder), 0.2 g of an electrolyte (solid LiF-LiCl-LiBr ternary all-lithium electrolyte, the same as in Example 1) and 0.03 g of a positive electrode material (the CoS electrode material prepared in Example 1) were added to the mold in sequence under argon protection in a glove box. A pressure of 14 MPa was applied, and the mold was removed after staying for 20 seconds. A nickel current collector was placed on both sides of the positive and negative electrodes of the cylinder obtained by compression molding to obtain a high-voltage, long-life, lightweight thermal battery.

[0088] After testing, the lightweight thermal battery was discharged at a constant current of 250mA / g at 500°C, with an open circuit voltage of 2.30V and a cut-off voltage of 1.3V, and the discharge capacity was about 197mAh / g.

[0089] Comparative Example 1:

[0090] A thermal battery is composed of lithium silicon alloy powder as the negative electrode, a solid LiF-LiCl-LiBr ternary all-lithium electrolyte (the same as the solid LiF-LiCl-LiBr ternary all-lithium electrolyte used in Example 1), a cobalt sulfide powder material (CoS) as the positive electrode, and two stainless steel current collectors.

[0091] Using a φ16 stainless steel cylindrical mold, add 0.1g of negative electrode, 0.2g of electrolyte and 0.05g of positive electrode material (cobalt sulfide powder material) to the mold in the argon atmosphere of the glove box, apply 14MPa pressure, stay for 20s and then remove the mold. Place a stainless steel current collector on both sides of the positive and negative electrodes of the pressed single battery and perform a discharge test. The battery is discharged at a constant current of 250mA / g at 500℃, with an open circuit voltage of 2.21V and a cut-off voltage of 1.30V, and the discharge capacity is about 130mAh / g.

[0092] Comparative Example 2:

[0093] The operation steps of Comparative Example 1 are followed, except that cobalt disulfide material (CoS2) is used instead of cobalt sulfide material (CoS). Specifically:

[0094] A φ16 stainless steel cylindrical mold was used, and 0.1 g of negative electrode (lithium silicon alloy powder), 0.2 g of electrolyte (solid LiF-LiCl-LiBr ternary all-lithium electrolyte, the same as in Example 1) and 0.05 g of positive electrode material (cobalt disulfide material) were sequentially added into the mold under an argon atmosphere in a glove box. A pressure of 14 MPa was applied, and the mold was removed after 20 seconds of dwelling. A stainless steel current collector was placed on both sides of the positive and negative electrodes of the single cell obtained by compression molding, and a discharge test was performed.

[0095] The obtained battery was subjected to a discharge test. When the battery was discharged at a constant current of 250 mA / g at 500° C., the open circuit voltage was 2.20 V, the cut-off voltage was 1.30 V, and the discharge capacity was about 191 mAh / g.

Claims

1. A lightweight thermal battery comprising: The invention adopts cobalt sulfide electrode material as positive electrode material, lithium silicon alloy as negative electrode material, inorganic lithium salt as electrolyte and current collector.

2. The lightweight thermal battery according to claim 1, characterized in that: The mass ratio of the positive electrode material to the negative electrode material is 1:(1-4), preferably 1:(1.2-3.5); and / or, The mass ratio of the negative electrode material to the electrolyte is 1:(1.5-2.2), preferably 1:(1-2).

3. The lightweight thermal battery according to claim 1, characterized in that: The inorganic lithium salt comprises lithium fluoride, lithium chloride and lithium bromide; and / or, The current collecting sheet is selected from one of stainless steel and nickel.

4. The lightweight thermal battery according to claim 3, characterized in that: The mass ratio of lithium fluoride, lithium chloride and lithium bromide is 1: (2.0-2.5): (7.0-7.5), preferably 1: (2.3-2.4): (7.1-7.2), and more preferably 1: (2.30-2.35): (7.15-7.20).

5. The lightweight thermal battery according to claim 1, characterized in that: The cobalt sulfide electrode material comprises a stainless steel felt substrate and cobalt sulfide; Preferably, the cobalt sulfide is electrodeposited on a stainless steel felt substrate using cyclic voltammetry; More preferably, in the cobalt sulfide electrode material, the content of cobalt sulfide is 70 to 90 wt%, preferably 80 to 90 wt%.

6. The lightweight thermal battery according to claim 5, characterized in that: The cobalt sulfide electrode material is prepared by the following steps: (1) adding a soluble cobalt salt and thiourea into water to obtain a mixed aqueous solution; (2) Using the mixed aqueous solution obtained in step (1) as an electrolyte and stainless steel felt as a substrate, cyclic voltammetry is used to electrodeposit cobalt sulfide to obtain the cobalt sulfide electrode material.

7. The lightweight thermal battery according to claim 6, characterized in that: In the step (1): The soluble cobalt salt is selected from at least one of cobalt chloride and cobalt nitrate; and / or, The molar ratio of the soluble cobalt salt to thiourea is 1:(15-30), preferably 1:(20-25); and / or, In the mixed aqueous solution, the concentration of the soluble cobalt salt is 0.04 to 0.06 mol / L, preferably 0.05 to 0.06 mol / L.

8. The lightweight thermal battery according to claim 6, characterized in that: In the step (2): The thickness of the stainless steel felt is 0.3-0.6 μm, preferably 0.4-0.45 μm; and / or, The electrodeposition conditions are: potential interval of 1.2 to 0.2 V, scan rate of 4 to 6 mV / s, scan number of 5 to 7; and / or, The method further comprises cleaning and drying steps after the electrodeposition.

9. A method for preparing the lightweight thermal battery according to any one of claims 1 to 8, comprising: The negative electrode material, electrolyte and positive electrode material are sequentially added into the mold for pressing and forming, and current collectors are placed on both sides of the positive and negative electrodes after demoulding to obtain the lightweight thermal battery.

10. The method for preparing a lightweight thermal battery according to claim 9, characterized in that: The conditions for the compression molding are: a pressure of 12 to 16 MPa and a residence time of 20 to 30 seconds.

Images