Radioactive source for an isotopic cell and method for its production, isotopic cell

Abstract

The present application belongs to the technical field of isotope battery, and specifically provides a radioactive source for an isotope battery, a preparation method thereof and the isotope battery. The present application aims to solve the problems that the existing radioactive source is not easy to prepare a substrate-free radioactive source film during preparation, and the existing radioactive source film is easy to damage the radioactive source when connected with a semiconductor transducer element. To this end, the radioactive source comprises a substrate layer, a radioactive source layer and a connecting layer connected in sequence, the substrate layer is connected to one side of the radioactive source layer and can be separated from the radioactive source layer, and the connecting layer is provided with adhesion and can transmit the energy radiated by the radioactive source layer. The radioactive source of the present application is convenient to prepare and has adhesion itself, and can be directly adhered to the semiconductor transducer element when used, without damaging the radioactive source.

Description

Technical Field

[0001] This invention belongs to the field of isotope battery technology, specifically providing a radioactive source for isotope batteries, a method for preparing the same, and an isotope battery. Background Technology

[0002] An isotope battery is a device that converts the energy released from the decay of radioactive isotopes into electrical energy. It was proposed by British physicist Henry Moseley in 1913 and developed into a novel power source in the 1960s. Compared to traditional chemical batteries and solar cells, isotope batteries have significant advantages in terms of lifespan, energy density, and environmental adaptability, making them promising for applications in representative fields such as implantable medical devices, positioning beacons, IoT chips, marine and polar power supplies, and space power supplies.

[0003] Isotope batteries come in many varieties. Based on the voltage provided, nuclear batteries can be divided into high-voltage (hundreds to thousands of volts) and low-voltage (tens of millivolts to about one volt). Based on the energy conversion method, they can be divided into direct conversion and indirect conversion. Based on the energy conversion mechanism, they include direct charging, thermal energy, electron-excited (β-radiation volt) type, and photon-excited β-radiation volt type. Compared to other types, the electron-excited β-radiation volt isotope battery utilizes the interaction between β particles released from the decay of a radioactive source and the semiconductor transducer material. This interaction generates a large number of electron-hole pairs within the semiconductor material, which are then separated under the influence of a built-in electric field and transported to the corresponding electrodes for collection, thus achieving the conversion and output of electrical energy. The greatest advantage of this type of battery lies in its semiconductor material basis, achieving a preliminary industrialization level in integration technology and product development. Most importantly, its output power is in the μW-mW range, basically meeting the power requirements of low-power electronic devices. Furthermore, its ease of integration, quiet operation, and DC output characteristics meet the needs of various electronic devices, making it suitable for a wide range of applications.

[0004] Electron-excited beta-radiation isotope cells consist of a radiation source, electrodes, and semiconductor transducers. Currently, the fabrication, loading, and assembly of radiation sources face the following challenges: 1) Substrate-free nanoscale radiation source films are extremely difficult to fabricate. The thicker the substrate, the more pronounced the self-absorption effect of decaying particles, reducing the energy conversion efficiency and utilization rate of the radiation source. Simultaneously, a thicker substrate results in a larger isotope cell volume, reducing the power density per unit volume and hindering miniaturization. Therefore, practical applications require substrate-free radiation sources or substrates that are as thin as possible and possess excellent comprehensive mechanical properties. However, fabricating substrate-free films for nanoscale radiation sources is extremely difficult. Even when substrate-free films are obtained through precise fabrication methods, they will curl and be destroyed under surface tension. 2) The connection and assembly of the radiation source film and semiconductor transducers can damage the radiation source. Currently, the connection methods between the radiation source film and semiconductor transducers include welding or adhesive bonding. When welding is used for connection, the heat effect of welding can cause local damage to the radioactive source, reducing its performance. When adhesive bonding is used, the adhesive results in a larger gap between the radioactive source and the semiconductor transducer, reducing the utilization rate of the radioactive source and ultimately causing a decrease in the power of the isotope cell.

[0005] Therefore, how to effectively obtain substrate-free radioactive source films and perform non-destructive connection and assembly of radioactive source films and semiconductor transducer units is of great significance for improving the energy conversion efficiency and utilization rate of radioactive sources. Summary of the Invention

[0006] The present invention aims to solve the above-mentioned technical problems, namely, to solve the problems that it is not easy to prepare a substrate-free radioactive source thin film during the preparation of existing radioactive sources, and that the existing radioactive source thin film is easily damaged when connected to a semiconductor transducer.

[0007] In a first aspect, the present invention provides a radioactive source for an isotope battery, the radioactive source comprising a substrate layer, a radioactive source layer and a connecting layer connected in sequence, the substrate layer being connected to one side of the radioactive source layer and separable from the radioactive source layer, and the connecting layer being configured to have adhesive properties and be capable of transmitting the energy radiated by the radioactive source layer.

[0008] In the preferred embodiment of the radioactive source for isotope batteries described above, the connecting layer is a carbon nanotube array perpendicular to the radioactive source layer, and the ends of two or more carbon nanotubes on the side of the carbon nanotube array away from the radioactive source layer are connected to form a knot.

[0009] In the preferred embodiment of the radioactive source for isotope batteries described above, the carbon nanotubes in the carbon nanotube array are one or a combination of single-walled carbon nanotubes or double-walled carbon nanotubes.

[0010] In the preferred embodiment of the above-mentioned radioactive source for isotope batteries, the length of the carbon nanotubes in the carbon nanotube array is ≤500nm.

[0011] In the preferred embodiment of the above-described radioactive source for isotope batteries, the surface roughness of the substrate layer is ≤100nm; and / or the substrate layer is made of silicon.

[0012] In the preferred embodiment of the radioactive source for isotope batteries described above, a protruding member is connected to the side of the substrate layer away from the radioactive source layer so as to separate the substrate layer from the radioactive source layer through the protruding member.

[0013] In the preferred embodiment of the radioactive source for isotope batteries described above, the protruding member is made of a magnetic material.

[0014] In the preferred embodiment of the above-described radioactive source for isotope batteries, the number of protruding members is multiple and they are spaced apart along the length direction of the substrate layer.

[0015] In the preferred embodiment of the above-mentioned radioactive source for isotope batteries, the distance from the top to the bottom of the protruding member is ≥1mm.

[0016] In the preferred embodiment of the radioactive source for isotope batteries described above, the radioactive source in the radioactive source layer is one of the following: an α-radioactive source, a β-radioactive source, a γ-radioactive source, or a neutron source, or a mixed source composed of multiple radioactive sources.

[0017] In the preferred embodiment of the radioactive source for isotope batteries described above, the thickness of the radioactive source layer is ≤1μm.

[0018] In the preferred embodiment of the radioactive source for isotope batteries described above, the carbon nanotubes in the carbon nanotube array are modified with metal nanoparticles, which are made of metal hydrogen storage materials.

[0019] In the preferred embodiment of the above-mentioned radioactive source for isotope batteries, the size of the metal nanoparticles is ≤50nm.

[0020] In a second aspect, the present invention provides a method for preparing a radioactive source, the method comprising the following steps: S100: preparing a radioactive source layer on one side of a substrate layer; S200: preparing a connecting layer on the side of the radioactive source layer away from the substrate layer, thereby obtaining a radioactive source.

[0021] In the preferred embodiment of the above-mentioned method for preparing a radioactive source, step S200 specifically includes the following steps: S210: Preparing Ni on the side surface of the radioactive source layer away from the substrate layer.a Co b Ti c Re d Catalytic layer; S220: Ni is produced by catalytic cracking. a Co b Ti c Re d A carbon nanotube array is vertically and oriented to grow on the surface of the radioactive source layer for the catalyst; S240: the carbon nanotubes of the carbon nanotube array are surface modified so that the ends of two or more carbon nanotubes on the side of the carbon nanotube array away from the radioactive source layer are connected to form a junction, thereby obtaining a radioactive source.

[0022] In the preferred embodiment of the above-mentioned method for preparing a radioactive source, before performing step S240, the preparation method further includes the following step: S230: modifying the carbon nanotubes in the carbon nanotube array using metal nanoparticles.

[0023] In the preferred embodiment of the above-mentioned method for preparing a radioactive source, in step S100, the radioactive source layer is prepared by any one of magnetron sputtering, thermal deposition, laser deposition, electron beam deposition, electroplating, electroless plating, pulsed laser deposition, and MOCVD; in step S210, the Ni is prepared by any one of magnetron sputtering, thermal deposition, laser deposition, electron beam deposition, electroplating, electroless plating, pulsed laser deposition, and MOCVD. a Co b Ti c Re d Catalytic layer.

[0024] In a third aspect, this invention provides an isotope battery comprising the aforementioned radioactive source.

[0025] When adopting the above technical solution, the radiation source of the present invention includes a substrate layer, a radiation source layer, and a connecting layer. The radiation source layer is located between the substrate layer and the connecting layer. The substrate layer is provided to facilitate the preparation of the radiation source layer (i.e., the radiation source thin film) using the substrate layer as a support. This allows the substrate layer to be separated from the radiation source layer, so that the substrate layer can be peeled off from the radiation source layer after the radiation source is assembled and used. This results in the radiation source retaining only the radiation source layer and the connecting layer, avoiding the absorption of energy from the radiation source by the substrate layer, thereby ensuring the energy conversion efficiency of the radiation source. In addition, by setting the connecting layer to be adhesive and able to smoothly transfer the energy radiated by the radiation source layer, when assembling the radiation source with the semiconductor transducer element, the connecting layer can be directly bonded to the semiconductor transducer element without welding or gluing. This protects the integrity of the radiation source from damage and allows the energy of the radiation source layer to be smoothly transferred to the semiconductor transducer element, improving the utilization efficiency of the radiation source.

[0026] Furthermore, the connecting layer is set as a carbon nanotube array, and a knot is formed on the side of the carbon nanotube array away from the radiation source layer. This setting facilitates the preparation of the connecting layer. The knot at the end of the carbon nanotube array has strong adhesion, making it easy to use. Moreover, the connecting layer will not be damaged by radiation after long-term use, resulting in a long service life.

[0027] Furthermore, compared to carbon nanotube arrays formed using multi-walled carbon nanotubes, choosing single-walled and / or double-walled carbon nanotubes to form carbon nanotube arrays makes it easier to connect the ends of two or more carbon nanotubes into knots during the surface modification process to form knots. This process is less difficult and results in a relatively large number of knots, ensuring the adhesion of the connecting layer.

[0028] Furthermore, using silicon products to prepare the substrate layer is low-cost and convenient.

[0029] Furthermore, the surface roughness of the substrate layer is ≤100nm, ensuring that the surface of the substrate layer is smooth enough so that the radiation source is not damaged when the substrate layer is peeled off from the radiation source layer, thereby ensuring the performance of the radiation source.

[0030] Furthermore, a protruding member is provided on one side of the substrate layer. This arrangement, by using the protruding member as a force application point, enables the substrate layer to be easily peeled off from the radiation source layer.

[0031] Furthermore, by using magnetic materials to prepare protruding components, the protruding components can be magnetically attracted and fixed to electromagnetic devices, and the substrate can be peeled off using the protruding components. This allows for automated production by peeling off the substrate using automated equipment.

[0032] Furthermore, metal nanoparticles are prepared using metal hydrogen storage materials, and carbon nanotubes are modified. The metal hydrogen storage materials can absorb and store hydrogen, thereby increasing the hydrogen absorption of the radioactive source and further increasing the energy of the radioactive source.

[0033] Furthermore, the metal nanoparticles are limited to within 50 nm to avoid the metal nanoparticles being too large and affecting the adhesion of the carbon nanotube array. Limiting the metal nanoparticles to within 50 nm can effectively improve the energy utilization rate of the radiation source and ensure that the carbon nanotube array has good adhesion, so as to facilitate the bonding and use of the radiation source and semiconductor transducer.

[0034] Furthermore, the method for preparing the radioactive source of the present invention includes first preparing a radioactive source layer on the side of a substrate layer, thereby forming a thin film on the surface of the substrate layer as a radioactive source layer, and then preparing a bonding layer on the surface of the radioactive source layer to obtain a radioactive source with adhesive properties. The preparation process is simple, and the obtained radioactive source itself has adhesive properties. When in use, it can be directly attached to a semiconductor transducer element, and the energy of the radioactive source can be smoothly transferred to the semiconductor transducer element, thereby improving the energy utilization rate of the radioactive source.

[0035] Furthermore, the step of fabricating the connecting layer specifically includes fabricating Ni on the side surface of the radiation source layer. a Co b Ti c Re d Catalytic layer, followed by Ni a Co b Ti c Re d A carbon nanotube array is vertically and oriented on the surface of the radioactive source layer to act as a catalyst. The surface of the carbon nanotube array is modified to form multiple knots at the ends of the carbon nanotubes, thereby giving the connecting layer strong adhesion. With this configuration, the carbon nanotube array has strong adhesion and can successfully transfer energy from the radioactive source layer.

[0036] Furthermore, before surface modification of the carbon nanotube array, metal nanoparticles are used to modify the carbon nanotube array. When the radioactive source in the radioactive source layer is 3H, the power of the radioactive source can be increased, thereby further improving the performance of the radioactive source. Attached Figure Description

[0037] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0038] Figure 1 This is a schematic diagram of the structure of the radioactive source of the present invention;

[0039] Figure 2 This is a schematic diagram of the assembly of the radiation source and the semiconductor transducer element of the present invention;

[0040] Figure 3 This is a flowchart of the method for preparing the radioactive source of the present invention.

[0041] Figure 4 This is a flowchart of a specific embodiment of the method for preparing the radioactive source of the present invention.

[0042] List of reference numerals :

[0043] 1. Substrate layer; 2. Radiation source layer; 3. Connecting layer; 4. Protrusion member; 5. Semiconductor transducer element. Detailed Implementation

[0044] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0045] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through other components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] Specifically, such as Figure 1 As shown, the radiation source of the present invention includes a substrate layer 1, a radiation source layer 2, and a connecting layer 3.

[0047] The radioactive source layer 2 is located between the substrate layer 1 and the connecting layer 3. The substrate layer 1 is connected to one side of the radioactive source layer 2 and can be separated from the radioactive source layer 2. The connecting layer 3 is configured to have adhesive properties and can transmit the energy radiated by the radioactive source layer 2.

[0048] The radiation source of the present invention includes a substrate layer 1, a radiation source layer 2, and a connecting layer 3. The radiation source layer 2 is disposed between the substrate layer 1 and the connecting layer 3. By configuring the connecting layer 3 to have adhesive properties and be able to smoothly transfer the energy radiated by the radiation source layer 2, the radiation source of the present invention itself has adhesive properties. When connected and assembled with the semiconductor transducer element 5 (see reference...), Figure 2 The connecting layer 3 can be directly bonded to the semiconductor transducer element 5 without welding or adhesive bonding, thus avoiding damage to the radiation source. Furthermore, the energy radiated by the radiation source layer 2 can be smoothly transferred to the semiconductor transducer element 5 through the connecting layer 3, ensuring the utilization rate of the radiation source and effectively maintaining the power of the isotope cell when applied. In addition, the substrate layer 1 is designed to be separable from the radiation source layer 2. The substrate layer 1 serves as a support substrate during the fabrication of the radiation source layer 2. After assembling the radiation source and the semiconductor transducer element 5, the substrate layer 1 can be removed (see reference...). Figure 2 This avoids absorbing energy from the radioactive source in practical applications and improves the energy utilization rate of the radioactive source.

[0049] It should be noted that the present invention does not impose any restrictions on the specific structure of the connecting layer 3, as long as the connecting layer 3 has adhesive properties and can smoothly transmit the energy radiated by the radiation source layer 2. In practical applications, those skilled in the art can customize the specific structure of the connecting layer 3 according to actual needs. Adjustments and changes to the structure of the connecting layer 3 do not deviate from the basic principles of the present invention and should be limited to the protection scope of the present invention.

[0050] Preferably, the connecting layer 3 is a carbon nanotube array perpendicular to the radiation source layer 2, with the ends of two or more carbon nanotubes connected together to form a knot on the side of the carbon nanotube array away from the radiation source layer 2.

[0051] By setting the connecting layer 3 as a carbon nanotube array, and forming a junction on the side of the carbon nanotube array away from the radiation source layer 2, this configuration facilitates the direct fabrication of the connecting layer 3 on the radiation source layer 2. Furthermore, the junction of the carbon nanotube array exhibits strong adhesion, making it easier to use. In addition, setting the connecting layer 3 as a carbon nanotube array ensures that its adhesion remains unaffected by radiation over extended use, resulting in a long service life.

[0052] Preferably, the carbon nanotubes in the carbon nanotube array are one or a combination of single-walled carbon nanotubes or double-walled carbon nanotubes.

[0053] Single-walled carbon nanotubes and / or multi-walled carbon nanotubes are chosen to form carbon nanotube arrays. Compared with multi-walled carbon nanotubes, single-walled carbon nanotubes and multi-walled carbon nanotubes make it easier to connect the ends of two or more carbon nanotubes to form knots during the surface modification of the carbon nanotube array to form knots, which facilitates the modification process. In addition, the number of knots obtained during the modification process is relatively large, thereby improving the adhesion of the connecting layer 3.

[0054] Preferably, the length of the carbon nanotubes in the carbon nanotube array is ≤500nm.

[0055] By controlling the length of the carbon nanotubes in the carbon nanotube array to 500 nm or less, the radiation source can be kept in a small volume.

[0056] Although the length of the carbon nanotubes in the carbon nanotube array is ≤500 nm as described above, this should not affect the scope of protection of this invention. In practical applications, those skilled in the art can set the length of the carbon nanotubes in the carbon nanotube array according to the required volume of the radioactive source and the isotope battery. For example, the length of the carbon nanotubes in the carbon nanotube array can be set to 600 nm, or 700 nm, etc. Such adjustments and changes to the length of the carbon nanotubes in the carbon nanotube array do not deviate from the basic principles of this invention and should be limited to the scope of protection of this invention. Of course, it is still preferable to make the length of the carbon nanotubes in the carbon nanotube array ≤500 nm, which is suitable for most radioactive sources and isotope batteries, and its production cost is relatively low.

[0057] It should be noted that this invention does not impose any restrictions on the specific structure and material of the substrate layer 1, as long as the substrate layer 1 can be separated from the radiation source layer 2 so that the surface of the radiation source no longer has the substrate layer 1 when in use. In practical applications, those skilled in the art can set the structure and material of the substrate layer 1 according to actual needs. For example, the substrate layer 1 can be set as a thin metal layer, or it can be set as a silicon-containing wafer, etc. Such adjustments and changes to the structure and material of the substrate layer 1 do not deviate from the basic principles of this invention and should be limited to the protection scope of this invention.

[0058] Preferably, the surface roughness of substrate 1 is ≤100nm.

[0059] The surface roughness of substrate 1 is made ≤100nm, making the surface of substrate 1 sufficiently smooth. When substrate 1 is peeled off, damage to the radiation source layer 2 can be avoided, thereby improving the utilization efficiency of the radiation source.

[0060] Although the surface roughness of substrate 1 is described above as ≤100nm, this should not limit the scope of protection of this invention. In practical applications, those skilled in the art can also set the surface roughness of substrate 1 to be greater than 100nm, as long as substrate 1 can be easily separated from the radiation source layer 2. Such adjustments and changes to the surface roughness of substrate 1 do not deviate from the basic principles of this invention and should be limited to the scope of protection of this invention. Of course, it is preferable to set the surface roughness of substrate 1 to ≤100nm. Within this range, separating substrate 1 will not substantially damage the radiation source layer 2, thus ensuring the performance of the radiation source.

[0061] Preferably, the substrate 1 is made of silicon.

[0062] Using silicon products to prepare substrate layer 1 offers a wide range of choices, a simple preparation process, and low cost.

[0063] Preferably, such as Figure 1 As shown, a protruding member 4 is fixedly connected to the side of the substrate layer 1 away from the radiation source layer 2, so as to separate the substrate layer 1 from the radiation source layer 2 through the protruding member 4.

[0064] A protruding member 4 is provided on the side of the substrate layer 1 away from the radiation source layer 2. The protruding member 4 is used as a force application point, and the substrate layer 1 and the radiation source layer 2 can be separated smoothly through the protruding member 4.

[0065] It should be noted that this invention does not impose any restrictions on the specific connection method between the protruding member 4 and the substrate layer 1, as long as the protruding member 4 can be used as a force application point to smoothly peel off the substrate layer 1. In practical applications, those skilled in the art can set the connection method between the protruding member 4 and the substrate layer 1 according to actual needs. For example, the protruding member 4 and the substrate layer 1 can be glued together, or the protruding member 4 and the substrate layer 1 can be made into an integral structure, or the protruding member 4 and the substrate layer 1 can be detachably connected, and so on. Such adjustments and changes to the specific connection method between the protruding member 4 and the substrate layer 1 do not deviate from the basic principles of this invention and should all be limited to the protection scope of this invention.

[0066] Preferably, the number of protruding members 4 is multiple and they are spaced apart along the length direction of the substrate layer 1.

[0067] Setting multiple protruding members 4 can increase the number of force application points, allowing force to be applied from multiple directions simultaneously, which can better peel off the substrate layer 1.

[0068] Preferably, the protruding member 4 is made of a magnetic material.

[0069] The protrusion component 4 is prepared using magnetic materials, so that the protrusion component 4 can be connected to an electromagnetic device by magnetic force, and can be used with automated equipment to remove the substrate layer 1, thereby realizing automated production.

[0070] Preferably, the distance from the top to the bottom of the protruding member 4 is ≥1mm.

[0071] The height of the protruding component 4 is ≥1mm, which enables better identification and positioning of the protruding component 4, so as to facilitate the easy location and use of the protruding component 4.

[0072] Preferably, the radioactive source in the radioactive source layer 2 is one of the following: an α radioactive source, a β radioactive source, a γ radioactive source, or a neutron source, or a mixed source composed of multiple radioactive sources.

[0073] The radioactive sources within the radioactive source layer 2 are selected from one or more of the following: alpha, beta, gamma, or neutron sources, or a mixture of multiple sources, making the radioactive sources within the radioactive source layer 2 nanometer-scale radioactive sources. Alpha sources include, but are not limited to, […]. 208 Po、 210 Po、 228 Th、 232 U、 236 Pu、 238 Pu、 241 Am、 244 Cm or 248 Bk; β-radiation sources include, but are not limited to 3 H, 39 Ar、 85 Kr、 90 Sr、 106 Ru、 113m Cd, 152 Sb, 147 Pm, 151 Sm or 155 Eu; gamma radiation sources include but are not limited to 55 Fe、 57 Co、 60 Co or 137 Cs; Neutron sources include but are not limited to 252 Cf.

[0074] Preferably, the thickness of the radioactive source layer 2 is ≤1μm.

[0075] By controlling the thickness of the radioactive source layer 2 to within 500 nm, the radioactive source can be kept in a small size, at a low cost, and is applicable to most types of isotope batteries.

[0076] Although the thickness of the radioactive source layer 2 is described above as ≤1μm, this does not affect the scope of protection of this invention. In practical applications, those skilled in the art can set the thickness of the radioactive source layer 2 according to factors such as the required size of the radioactive source, the size of the isotope cell, and production costs. For example, the thickness of the radioactive source layer 2 can be set to 2μm, or 3μm, etc. Such adjustments and changes to the thickness of the radioactive source layer 2 do not deviate from the basic principles of this invention and should all be limited to the scope of protection of this invention. Of course, it is still preferable to make the thickness of the radioactive source layer 2 ≤1μm, which is suitable for most specifications of radioactive sources and isotope cells, and its production cost is low.

[0077] Preferably, the carbon nanotubes in the carbon nanotube array are modified with metal nanoparticles, which are made of metal hydrogen storage materials.

[0078] Metal nanoparticles are fabricated using metallic hydrogen storage materials, which are then used to modify carbon nanotubes. These metallic hydrogen storage materials can absorb and store hydrogen, thereby increasing the hydrogen absorption capacity of the radioactive source and further improving its energy and utilization efficiency. The metallic hydrogen storage materials include, but are not limited to, alloys composed of titanium, vanadium, zirconium, magnesium, nickel, and other alloys in any proportion thereof.

[0079] Preferably, the size of the metal nanoparticles is ≤50nm.

[0080] Limiting the size of metal nanoparticles to 50 nm or less can prevent excessively large metal nanoparticles from affecting the adhesion of carbon nanotube arrays, thus enabling the radiation source to have good adhesion performance.

[0081] The present invention also provides a method for preparing a radioactive source, for preparing the above-mentioned radioactive source.

[0082] Specifically, such as Figure 3 As shown, the preparation method of the present invention specifically includes the following steps:

[0083] S100: A radiation source layer is prepared on one side of the substrate layer.

[0084] Specifically, a radiation source layer can be prepared on the side of the substrate using any of the following methods: magnetron sputtering, thermal deposition, laser deposition, electron beam deposition, electroplating, electroless plating, pulsed laser deposition, and MOCVD.

[0085] S200: A bonding layer is prepared on the side of the radioactive source layer away from the substrate layer to obtain the radioactive source.

[0086] The method for preparing the radioactive source of the present invention involves first preparing a radioactive source layer on one side of a substrate, and then preparing a connecting layer on the side of the radioactive source layer. The preparation process is simple, the obtained radioactive source itself has adhesive properties, and it does not affect the energy release of the radioactive source layer during use, thus effectively improving the utilization efficiency of the radioactive source.

[0087] Preferably, step S200 specifically includes steps S210, S220 and S230.

[0088] Specifically, such as Figure 4 As shown, step S200 specifically includes the following steps:

[0089] S210: Ni is prepared on the side of the radiation source layer away from the substrate. a Co b Ti c Re d Catalytic layer, wherein 0.3≤a≤1, 0.3≤b≤1, 0<c≤0.2, 0≤d≤0.1.

[0090] Specifically, Ni can be prepared on the side surface of the radiation source layer using any of the following methods: magnetron sputtering, thermal deposition, laser deposition, electron beam deposition, electroplating, electroless plating, pulsed laser deposition, and MOCVD. a Co b Ti c Re d Catalytic layer.

[0091] S220: Ni is produced by catalytic cracking. a Co b Ti c Re d A layer of carbon nanotube arrays was vertically and oriented on the surface of the radioactive source layer to act as a catalyst. Ni a Co b Ti c Re d Using it as a catalyst to prepare carbon nanotube arrays results in faster growth of carbon nanotubes and better performance.

[0092] S240: The carbon nanotubes in the carbon nanotube array are surface modified so that the ends of two or more carbon nanotubes on the side of the carbon nanotube array away from the radiation source layer are connected to form a junction, thereby obtaining a radiation source.

[0093] In this process, the product is placed in an electron beam processing device to modify the surface of the carbon nanotubes, thereby connecting the ends of the carbon nanotubes into joints and enhancing the adhesion of the carbon nanotube connecting layer.

[0094] Preferably, such as Figure 4 As shown, before performing step S240, the preparation method of the present invention further includes the following steps:

[0095] S230: Modify the carbon nanotubes in the carbon nanotube array using metal nanoparticles.

[0096] Modifying carbon nanotubes with metal nanoparticles can improve the energy transfer efficiency of carbon nanotube arrays. Furthermore, setting the modification step before the carbon nanotubes is modified can avoid the metal nanoparticles affecting the adhesion of the carbon nanotube array, thus ensuring that the carbon nanotube array has good adhesion performance.

[0097] The method for preparing the radioactive source of the present invention will be described in detail below with reference to three specific embodiments. These embodiments are intended to help those skilled in the art to further understand the present invention, but do not limit the scope of the invention in any way. It should be noted that any modifications and improvements made by those skilled in the art without departing from the concept of the present invention should fall within the protection scope of the present invention.

[0098] Example 1

[0099] This embodiment uses a Si substrate as the substrate layer and selects... 63 Ni is used as the radioactive source for the radioactive source layer. The specific preparation process of the radioactive source is as follows:

[0100] S100: The substrate layer is ultrasonically cleaned with alcohol and then dried, followed by plasma cleaning to obtain a substrate layer with optimal surface cleanliness; subsequently, nanoscale ... 63 Ni radioactive source layer. The substrate layer has dimensions of 20 mm (length) × 20 mm (width) × 0.5 mm (thickness) and a surface roughness of 50 nm; the resulting... 63 The thickness of the Ni radioactive source layer is 700 nm.

[0101] S200: Employed using magnetron sputtering method in 63 Ni is fabricated on the side of the Ni radioactive source layer away from the substrate. 0.55 Co 0.25 Ti 0.16 Re 0.04 Catalytic layer, wherein Ni 0.55 Co 0.25 Ti 0.16 Re 0.04 The thickness of the catalyst layer is 6 nm.

[0102] S300: Ni is produced by catalytic cracking. 0.55 Co 0.25 Ti 0.16 Re 0.04 For catalyst in 63 A layer of carbon nanotube array is vertically and directionally grown on the surface of the Ni radioactive source layer, wherein the length of the carbon nanotubes in the carbon nanotube array is 400 nm. The process is carried out in a mixed atmosphere of Ar, H2 and C2H2 at a temperature of 700 °C for 65 min; wherein the Ar, H2 and C2H2 gas flow rates are: Ar: 100 sccm, H2: 260 sccm and C2H2: 400 sccm.

[0103] S400: The overall product obtained in step S300 is placed in an electron beam processing device to modify the surface of the carbon nanotubes, so that the ends of two or more carbon nanotubes on the side of the carbon nanotube array away from the radiation source layer are connected to form a junction, thus obtaining the final radiation source; wherein, the electron beam processing device is an electron accelerator with a processing power of 10kW and a processing time of 50min.

[0104] Example 2

[0105] This embodiment uses a Si substrate as the substrate layer and selects... 3H is used as the radioactive source for the radioactive source layer, and the specific preparation process of the radioactive source is as follows:

[0106] S100: The substrate was ultrasonically cleaned with alcohol and then dried, followed by plasma cleaning to obtain a substrate with optimal surface cleanliness. Subsequently, a nanoscale Ti layer was fabricated on one side of the substrate using magnetron sputtering. The substrate dimensions were 20 mm (length) × 20 mm (width) × 0.5 mm (thickness), with a surface roughness of 50 nm. The resulting nanoscale Ti layer had a thickness of 400 nm.

[0107] S200: Ni is prepared on the side of the Ti layer away from the substrate layer using magnetron sputtering. 0.55 Co 0.25 Ti 0.16 Re 0.04 Catalytic layer, wherein Ni 0.55 Co 0.25 Ti 0.16 Re 0.04 The thickness of the catalyst layer is 6 nm.

[0108] S300: Ni is produced by catalytic cracking. 0.55 Co 0.25 Ti 0.16 Re 0.04 A carbon nanotube array was vertically and oriented on the side of the Ti layer away from the substrate to act as a catalyst, wherein the length of the carbon nanotubes in the array was 500 nm. The process was carried out in a mixed atmosphere of Ar, H2, and C2H2 at 700 °C for 65 min; the Ar, H2, and C2H2 gas flows met the following parameters: Ar: 100 sccm, H2: 260 sccm, and C2H2: 400 sccm.

[0109] S400: The overall product obtained in step S300 is placed in an electron beam processing device to modify the surface of the carbon nanotubes, so that the ends of two or more carbon nanotubes on the side of the carbon nanotube array away from the Ti layer are connected to form a junction, thereby obtaining a radioactive source substrate; wherein, the electron beam processing device is an electron accelerator with a processing power of 10kW and a processing time of 50min.

[0110] S500: The radioactive source substrate is activated and hydrogen isotopes are absorbed until saturation is achieved, thus obtaining the radioactive source. Specifically, a vacuum of 5 × 10⁻⁶ is drawn. -4 Below Pa, the radioactive source substrate obtained in step S400 is heated to 600±50℃ and activated for 30±5min; then hydrogen gas is introduced to 5kPa to absorb hydrogen until saturation, thus obtaining the final radioactive source.

[0111] Example 3

[0112] This embodiment uses a Si substrate as the substrate layer and selects... 3 H is used as the radioactive source for the radioactive source layer, and the specific preparation process of the radioactive source is as follows:

[0113] S100: The substrate was ultrasonically cleaned with alcohol and then dried, followed by plasma cleaning to obtain a substrate with optimal surface cleanliness. Subsequently, a nanoscale Ti layer was fabricated on one side of the substrate using magnetron sputtering. The substrate dimensions were 20 mm (length) × 20 mm (width) × 0.5 mm (thickness), with a surface roughness of 50 nm. The resulting nanoscale Ti layer had a thickness of 400 nm.

[0114] S200: Ni is prepared on the side of the Ti layer away from the substrate layer using magnetron sputtering. 0.55 Co 0.25 Ti 0.16 Re 0.04 Catalytic layer, wherein Ni 0.55 Co 0.25 Ti 0.16 Re 0.04 The thickness of the catalyst layer is 6 nm.

[0115] S300: Ni is produced by catalytic cracking. 0.55 Co 0.25 Ti 0.16 Re 0.04 A carbon nanotube array was vertically and oriented on the side of the Ti layer away from the substrate to act as a catalyst, wherein the length of the carbon nanotubes in the array was 500 nm. The process was carried out in a mixed atmosphere of Ar, H2, and C2H2 at 700 °C for 65 min; the Ar, H2, and C2H2 gas flows met the following parameters: Ar: 100 sccm, H2: 260 sccm, and C2H2: 400 sccm.

[0116] S400: Titanium is used to modify carbon nanotubes in a carbon nanotube array to obtain titanium-loaded carbon nanotubes, where the titanium loading is 10 ± 2 wt.%. The specific operation process is as follows: Step 1: Acidified carbon nanotubes and polyvinylpyrrolidone (PVP) are added to a tetrabutyl titanate solution and ultrasonically mixed to obtain mixed solution A. The pH of mixed solution A is then adjusted to 10–12, and hydrazine hydrate solution is added, resulting in mixed solution B. The mass ratio of acidified carbon nanotubes to tetrabutyl titanate is 13 g: 0.1 mol, the concentration of the tetrabutyl titanate solution is 0.1–0.5 mol / L, and the mass of polyvinylpyrrolidone is 3%–10% of the mass of tetrabutyl titanate. Step 2: Mixed solution B obtained in Step 1 is stirred and reacted at 60–80°C, then cooled to room temperature and vacuum dried at 50°C to obtain titanium-modified carbon nanotubes.

[0117] S500: The overall product obtained in step S400 is placed in an electron beam processing device to modify the surface of the carbon nanotubes, so that the ends of two or more carbon nanotubes on the side of the carbon nanotube array away from the Ti layer are connected to form a junction, thereby obtaining a radioactive source substrate; wherein, the electron beam processing device is an electron accelerator with a processing power of 10kW and a processing time of 50min.

[0118] S600: The radioactive source matrix is ​​activated and hydrogen isotopes are absorbed to saturation, thereby obtaining a radioactive source. Specifically, a vacuum of 5 × 10⁻⁶ is drawn. -4 Below Pa, the radioactive source substrate obtained in step S500 is heated to 600±50℃ and activated for 30±5min; then hydrogen gas is introduced to 5kPa to absorb hydrogen until saturation, thus obtaining the final radioactive source.

[0119] Comparative Example 1

[0120] This comparative example uses a Si substrate as the substrate layer and selects... 63 Ni is used as the radioactive source for the radioactive source layer. The specific preparation process of the radioactive source is as follows:

[0121] The substrate was ultrasonically cleaned with alcohol and then dried, followed by plasma cleaning to obtain a substrate with optimal surface cleanliness. Subsequently, nanoscale nanoscale structures were fabricated on one side of the substrate using magnetron sputtering. 63 The Ni radioactive source layer is used to obtain the final radioactive source. The substrate layer has dimensions of 20 mm (length) × 20 mm (width) × 0.5 mm (thickness) and a surface roughness of 50 nm; the resulting radioactive source layer has a thickness of 700 nm.

[0122] Comparative Example 2

[0123] This comparative example uses a Si substrate as the substrate layer and selects... 3 H is used as the radioactive source for the radioactive source layer, and the specific preparation process of the radioactive source is as follows:

[0124] S100: The substrate layer is ultrasonically cleaned with alcohol and then dried, followed by plasma cleaning to obtain a substrate layer with optimal surface cleanliness. Subsequently, a nanoscale Ti layer is fabricated on one side of the substrate layer using magnetron sputtering, thus obtaining the radioactive source substrate. The substrate layer has dimensions of 20 mm (length) × 20 mm (width) × 0.5 mm (thickness) and a surface roughness of 50 nm; the thickness of the obtained nanoscale Ti layer is 400 nm.

[0125] S200: The radioactive source matrix is ​​activated and hydrogen isotopes are absorbed until saturation, thus obtaining the radioactive source. Specifically, a vacuum of 5 × 10⁻⁶ is drawn. -4 Below Pa, the radioactive source substrate obtained in step S100 is heated to 600±50℃ and activated for 30±5min; then hydrogen gas is introduced to 5kPa to absorb hydrogen until saturation, thus obtaining the final radioactive source.

[0126] The radiation sources obtained from the above embodiments and comparative examples were assembled with semiconductor transducers, and their power was measured using an IV meter. The power increase rate of Embodiment 1 relative to Comparative Example 1, and the power increase rates of Embodiments 2 and 3 relative to Comparative Example 2 were calculated using power calculations. Specifically, when assembling the radiation sources with the semiconductor transducers, the radiation sources of Embodiments 1 to 3 had their connecting layers directly bonded to the semiconductor transducers, while the radiation sources of Comparative Examples 1 and 2 were assembled with the semiconductor transducers using adhesive bonding.

[0127] Calculations based on the test data show that Example 1 has a 40% increase in power compared to Comparative Example 1; Example 2 has a 34.33% increase in power compared to Comparative Example 2; and Example 3 has a 71.64% increase in power compared to Comparative Example 2.

[0128] As can be seen from the above data, the radioactive source prepared by the method of the present invention has a significantly higher power than existing radioactive sources during use, thereby resulting in higher utilization efficiency of the radioactive source. Furthermore, the radioactive source is... 3 At H, the radiation source prepared by modifying the carbon nanotube array with metal nanoparticles has a significantly increased power and higher utilization efficiency compared to the radiation source prepared without modifying the carbon nanotube array.

[0129] Furthermore, the present invention also protects an isotope battery comprising the aforementioned radioactive source.

[0130] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A radioactive source for isotope batteries, characterized in that, The radiation source includes a substrate layer, a radiation source layer and a connecting layer connected in sequence. The substrate layer is connected to one side of the radiation source layer and can be separated from the radiation source layer. The connecting layer is configured to have adhesive properties and can transmit the energy radiated by the radiation source layer. The connecting layer is a carbon nanotube array perpendicular to the radiation source layer, with the ends of two or more carbon nanotubes connected together to form a knot on the side of the carbon nanotube array away from the radiation source layer.

2. The radioactive source for isotope batteries according to claim 1, characterized in that, The carbon nanotubes in the carbon nanotube array are one or a combination of single-walled carbon nanotubes or double-walled carbon nanotubes.

3. The radioactive source for isotope batteries according to claim 1, characterized in that, The surface roughness of the substrate layer is ≤100nm; and / or The substrate is made of silicon.

4. The radioactive source for isotope batteries according to claim 1, characterized in that, The substrate layer has a protruding member connected to the side away from the radiation source layer so as to facilitate separation of the substrate layer from the radiation source layer by means of the protruding member.

5. The radioactive source for isotope batteries according to claim 4, characterized in that, The number of protruding members is multiple and they are spaced apart along the length direction of the substrate layer.

6. The radioactive source for an isotope battery according to claim 4, characterized in that, The protruding component is made of magnetic material.

7. The radioactive source for an isotope battery according to claim 1, characterized in that, The radioactive source in the radioactive source layer is one of the following: alpha radioactive source, beta radioactive source, gamma radioactive source, or neutron source, or a mixed source composed of multiple radioactive sources.

8. The radioactive source for isotope batteries according to claim 1, characterized in that, The carbon nanotubes in the carbon nanotube array are modified with metal nanoparticles, which are made of metal hydrogen storage materials.

9. The radioactive source for an isotope battery according to claim 8, characterized in that, The size of the metal nanoparticles is ≤50nm.

10. A method for preparing a radioactive source for an isotope battery according to any one of claims 1 to 9, characterized in that, The preparation method includes the following steps: S100: A radiation source layer is prepared on one side of the substrate layer; S200: A bonding layer is prepared on the side of the radiation source layer away from the substrate layer to obtain a radiation source.

11. The method for preparing a radioactive source according to claim 10, characterized in that, Step S200 specifically includes the following steps: S210: Ni is prepared on the side of the radiation source layer away from the substrate layer. a Co b Ti c Re d Catalytic layer, wherein 0.3≤a≤1, 0.3≤b≤1, 0<c≤0.2, 0≤d≤0.1; S220: Ni is produced by catalytic cracking. a Co b Ti c Re d A layer of carbon nanotube array is vertically and oriented to grow a catalyst on the surface of the radiation source layer; S240: The carbon nanotubes of the carbon nanotube array are surface modified so that the ends of two or more carbon nanotubes on the side of the carbon nanotube array away from the radiation source layer are connected to form a junction, thereby obtaining a radiation source.

12. The method for preparing a radioactive source according to claim 11, characterized in that, Before performing step S240, the preparation method also The process includes the following steps: S230: Modifying the carbon nanotubes in the carbon nanotube array using metal nanoparticles.

13. An isotope battery, characterized in that, The radioactive source includes any one of claims 1 to 9.

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