Heating structure for fast activation thermal battery

Abstract

The application relates to a heating structure for a quick-activated thermal battery, which solves the existing problems of the current structure. The heating box structure is formed by pressing nickel sheet A, nickel sheet B, a heating sheet and a lead wire through an oil press, and the feature is that the nickel sheet B is punched with uniformly distributed holes, and a chord-shaped notch is cut on the circular edge, and the heating sheet leaks out from the notch. The application reduces the time sequence of heat transfer, cuts a notch on the edge of the porous nickel sheet, aligns the heating sheet with the heating box during the wrapping process, and does not need to specially perform eccentric exposure operation, thereby avoiding the problem of poor consistency of the heating box wrapping; meanwhile, the heating sheet at the notch position is kept in a fluffy state, and ignition is facilitated.

Description

Technical Field

[0001] This invention belongs to the field of pyrotechnics and power supply technology, specifically relating to a heating structure for a fast-activation thermal battery. Background Technology

[0002] Currently, there are two heating systems for thermal batteries. One is the iron-based heating system, which involves pressing powder into sheets. In this system, the heating agent can directly contact the positive electrode of the individual cell, while a highly conductive nickel sheet must be used to isolate it from the negative electrode. Because the iron-based heating agent has a slow burning rate, conducts electricity after combustion, and can maintain its shape before combustion, it is suitable for high-power, slow-activation thermal batteries. The other is the zirconium-based heating system, which involves making heating paper from the material using a papermaking process, and then punching it into the required heating sheet according to size requirements. In use, the heating sheet is wrapped between two nickel sheets. After the heating sheet burns, the heat is transferred to the individual cell through the nickel sheets. The zirconium-based heating agent has a faster burning rate and is suitable for fast-activation thermal batteries.

[0003] Existing zirconium heating systems involve prefabricating a heating box structure before use. Specifically, this involves preparing two nickel sheets and a heating element in advance. The heating element is placed on nickel sheet 1, and the lead wire is folded back to secure it. Then, nickel sheet 2 is folded back to completely overlap with nickel sheet 1. The two nickel sheets and the lead wire together enclose the heating element in the middle, forming the heating box. During operation, heat is conducted to the individual cells through the nickel sheets, while electron conduction is facilitated by the conductivity of the nickel sheets and the lead wire. A schematic diagram of the two nickel sheets is shown below. Figure 1 A schematic diagram of the heating box can be found here. Figure 2 .

[0004] The existing zirconium heating system heating box structure has the following drawbacks: (1) When wrapping the heating element with a double nickel sheet, the heating element should protrude 0.5mm from one edge of the double nickel sheet. The protruding part should be close to one end of the fire channel during assembly to facilitate ignition of the heating element. The packaging process of the heating box is entirely manual. It is difficult to ensure the consistency of the amount of heating element protrusion by visual inspection. If too much is exposed, heat will easily accumulate and affect the stability of electrical performance during operation. If too little is exposed, it will be difficult to ignite and affect the activation time.

[0005] (2) In order to reduce the contact resistance during the operation of the thermal battery, the heating box is pressed under a hydraulic press before use. Under this pressure, the porous and loose state between the heating elements is compacted. This is not conducive to the combustion of the heating elements and affects the combustion speed.

[0006] (3) During the operation of the thermal battery, the heating element is ignited from one edge and gradually burns through the entire heating element. The heat gradually increases and the molten electrolyte layer becomes conductive. The ignition process of the heating element proceeds gradually, and there is a time difference in the combustion process.

[0007] (4) After the heating element of the heating system is burned, it first heats the nickel sheet with a thickness of 0.05mm to 0.1mm. The heat is transferred to the individual cells through the nickel sheet. There is a time difference in the heat transfer process, which cannot achieve rapid heat transfer and affects the activation time of the thermal battery. Summary of the Invention

[0008] The purpose of this invention is to provide a heating structure for a fast-activation thermal battery. Through an improved design of the original nickel sheet, circular holes of the same size are punched into the nickel sheet, allowing the heat generated during the combustion of the heating element to be directly transferred to the individual battery cells, melting the electrolyte and activating the thermal battery. This improvement reduces the heat transfer time. Simultaneously, a notch is cut at the edge of the porous nickel sheet, aligning the heating element with the heating box during the wrapping process, eliminating the need for eccentric exposure and avoiding inconsistent packaging. Furthermore, the notched area of ​​the heating element remains fluffy, facilitating ignition.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: A heating structure for a fast-activation thermal battery is designed with a nickel sheet B. 25 to 30 holes with a diameter of 1.5 mm are punched on the surface of the nickel sheet B. At the same time, a notch of about 10 mm is cut off from one edge. The nickel sheets A and B are spot-welded together by leads.

[0010] During the packaging process of the heating box, the heating element is placed on the nickel sheet B and fixed with a lead wire. Then, the nickel sheet A is bent over to wrap the heating element. During the wrapping process, the heating element does not need to be exposed off-center from the edge of the nickel sheet B. After wrapping, the heating box is flattened and pressed under a hydraulic press.

[0011] During the assembly of the thermal battery, the notched part of nickel sheet B is aligned with the ignition channel on the edge of the thermal insulation battery shell to ensure that the heating element wrapped in the double nickel sheet is ignited through the ignition channel on the thermal insulation battery shell.

[0012] The diameter of the nickel sheet can be adjusted according to the outer diameter of the thermal battery, and the number of holes on the nickel sheet B can also be adjusted. The design can be optimized according to the activation time requirements and the size of the thermal battery itself.

[0013] The advantages and positive effects of this invention are: (1) The 1.5mm diameter hole punched on the surface of nickel sheet B allows the heat generated after the heating element burns to be directly transferred to the individual cell, reducing the process of heat transfer to the individual cell through the nickel sheet, quickly melting the electrolyte layer inside the individual cell, and activating the thermal battery more quickly.

[0014] (2) The structure at the 10mm notch of the nickel sheet B makes part of the heating element completely exposed outside the nickel sheet. After the heating box is pressed and flattened, the exposed part of the heating element bears relatively less pressure and is not compacted. The structure is relatively loose, which avoids the problem of unreliable ignition caused by the compaction of the heating element and improves the reliability of the heating element ignition.

[0015] (3) In the process of wrapping the heating element around the double nickel sheet, there is no need to deliberately expose the heating element off-center. The heating element is directly aligned with the edge of the nickel sheet and wrapped concentrically. This reduces the difficulty of wrapping and improves the consistency of the wrapping state of the heating box.

[0016] (4) It is easy to operate and has low design cost. It is applicable to thermal batteries of various sizes by changing the size. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a double nickel sheet in the background art of this invention. Figure 2 This is a schematic diagram of the heating box; Figure 3 The nickel sheet A involved in this invention; Figure 4 The nickel sheet B involved in this invention; Figure 5 This invention relates to a double nickel sheet; Figure 6 This invention relates to a heating box. Detailed Implementation

[0018] To further understand the content, features, and effects of this invention, the following embodiments are provided, and detailed descriptions are given in conjunction with the accompanying drawings: refer to Figures 3-6 A heating structure for a fast-activation thermal battery includes a nickel sheet A, a nickel sheet B, a lead wire, and a heating element.

[0019] refer to Figure 3 The selected nickel sheet A is made of nickel strip through machining. The diameter is selected according to the diameter of the single cell, and the thickness is generally 0.05mm to 0.1mm.

[0020] refer to Figure 4 The selected nickel sheet B can be processed by manually punching holes and cutting the edges on the surface of the nickel sheet A; alternatively, it can be stamped in one go using a mold.

[0021] refer to Figure 5 The prepared dual nickel sheet for the thermal battery is made by aligning nickel sheet A, nickel sheet B, and leads and spot welding them together using energy storage welding. There are generally 4 to 6 weld points.

[0022] refer to Figure 6A method for wrapping a heating box for a thermal battery is provided. The heating element is concentrically placed on nickel sheet B and secured with a lead wire. Nickel sheet A is folded in half and kept concentric with nickel sheet B. After this wrapping method is completed, the heating box is flattened and pressed under a hydraulic press. At this point, the heating element at the notch of nickel sheet B is not compacted, allowing the heating element to be reliably ignited.

[0023] The thermal battery using the aforementioned heating structure has a diameter of φ20.0mm and a height of 24.5mm. Its activation time can reach approximately 0.07s. After activation, the voltage-time curve is monitored, and the curve is smooth, stable, and noiseless, with stable output performance.

[0024] The described embodiments are only a part of the present invention, not all of it. Without departing from the principle of the present invention, the size, shape, number and shape of the nickel sheet can be designed according to the size of the individual unit, and all of these are within the protection scope of the present invention.

Claims

1. A heating structure for a fast-activation thermal battery, comprising nickel sheet A, nickel sheet B, a heating element, and leads pressed together by a hydraulic press to form a heating box structure, characterized in that: The nickel sheet B has evenly distributed holes punched in it, and a chord-shaped notch is cut out on its round edge, through which the heating element protrudes.

2. The heating structure for a fast-activation thermal battery according to claim 1, characterized in that: The nickel sheet B has 25 to 30 holes of 1.5 mm in diameter that are evenly distributed.

3. The heating structure for a fast-activation thermal battery according to claim 1, characterized in that: The notch chord length is 9-11mm.

4. The heating structure for a fast-activation thermal battery according to claim 1, characterized in that: During the process of nickel sheet A and nickel sheet B wrapping and pressing the heating element, the heating element is aligned with the heating box and does not leak out.

5. The heating structure for a fast-activation thermal battery according to claim 1, characterized in that: The heating element protruding from the notch is not compacted during the molding process of the heating box structure.

6. The heating structure for a fast-activation thermal battery according to claim 1, characterized in that: Nickel sheet A is made of nickel strip through machining. Its diameter is selected according to the diameter of the single cell, and its thickness is 0.05mm to 0.1mm.

7. The heating structure for a fast-activation thermal battery according to claim 1, characterized in that: Nickel sheet A, nickel sheet B, and lead wire are aligned and spot-welded together using energy storage welding, with 4 to 6 weld points.

8. The heating structure for a fast-activation thermal battery according to claim 1, characterized in that: The holes on nickel sheet B are made by hand punching or by punching them in one go using a mold.

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