Thin film stacked compact isotope battery

Abstract

The invention discloses a compact isotope battery with stacked thin films. The compact isotope battery comprises at least two power generation units which are stacked in sequence, the power generation unit comprises a first thin film part which can generate radioactive particles and serves as the positive electrode end of the power generation unit at the same time; the second thin film part is used for receiving the radioactive particles generated by the first thin film part and transduction and power generation; the third thin film part is used as a negative electrode end of the power generation unit; the second thin film piece is located between the first thin film piece and the third thin film piece. The thin film stacked compact isotope battery provided by the invention can solve the technical problem that an existing compact radiovolt effect isotope battery is relatively low in output power; the structure of the compact isotope battery is formed by stacking the thin films, so that the volume of the isotope battery is reduced, the output power of the isotope battery can be improved, and popularization and application of the radiovolt effect isotope battery are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of isotope batteries, and in particular to a compact isotope battery with a thin film stack. Background Art

[0002] Isotope batteries are devices that convert the energy released during the decay of radioactive isotopes into electricity. They hold broad application prospects in areas such as implantable medical devices, positioning beacons, IoT chips, power systems (particularly in marine and polar environments), and space power systems.

[0003] Among them, the Radiation-voltalic Isotope Battery (RVIB) utilizes beta particles to generate electron-hole pairs within a semiconductor. Using a self-contained power plant within the semiconductor, these electron-hole pairs are separated and collected to form a current and voltage power source. Its advantages lie in its output power, typically in the μW to mW range, which generally meets the power requirements of low-power electronic devices. It also boasts long lifespan, reliable performance, and micro-scalability, and can operate in harsh or extreme environments (such as deep space, the deep ocean, polar glaciers, deserts, underground, and the human body). Initial industrialization has been achieved in integrated process and product development, and it holds broad application prospects in the Internet of Things, chips, biomedicine, microelectromechanical systems (MEMS), and other fields.

[0004] At present, radiovoltaic isotope batteries, especially miniaturized or compact radiovoltaic isotope batteries, have low output power (nW-μW level) and low energy conversion efficiency (0.01%-3%), resulting in the inability of single-chip batteries to generate macroscopic power output, which affects the promotion and use of radiovoltaic isotope batteries.

[0005] In order to solve the technical problem of low output power of compact radiovoltaic effect isotope batteries, it is necessary to improve the existing compact radiovoltaic effect isotope batteries. Summary of the Invention

[0006] The present invention aims to provide a thin film stacked compact isotope battery to solve the technical problem of low output power of existing compact radiovoltaic effect isotope batteries.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] The present invention provides a compact thin-film stacked isotope battery comprising at least two sequentially stacked power-generating units. The power-generating units include a first thin-film element capable of generating radioactive particles and serving as the positive terminal of the power-generating unit; a second thin-film element for receiving the radioactive particles generated by the first thin-film element and converting them into electricity; and a third thin-film element serving as the negative terminal of the power-generating unit. The second thin-film element is positioned between the first and third thin-film elements. Using a thin-film stack as the structure of the compact isotope battery can reduce the battery's volume. Furthermore, the stacking of multiple power-generating units can increase the output power of existing compact radiovoltaic effect isotope batteries, facilitating their widespread use.

[0009] Preferably, the first film member comprises a hydrogen storage alloy film, the hydrogen storage alloy film adsorbing tritium; the hydrogen storage alloy film is capable of absorbing and storing tritium within a temperature range of ≤100°C;

[0010] The element composition of the hydrogen storage alloy film is Ti a Zr b V c Nb d Ni e M f ;

[0011] Wherein, M is one of Mg, Al, Cr, Mn, Fe, Co, and Mo;

[0012] Among them, the subscripts a, b, c, d, e, and f refer to the proportion of the number of atoms of the corresponding elements in the hydrogen storage alloy film, and the range of the proportion of each element is: 0.1≤a≤0.35, 0.1≤b≤0.35, 0.1≤c≤0.25, 0.1≤d≤0.35,

[0013] 0.05≤e≤0.3, 0.05≤f≤0.3, and a+b+c+d+e+f=1.

[0014] The output power of compact radiovoltaic isotope batteries is also affected by the performance of the radioactive source. In existing technologies, the adsorption temperature of tritium gas by hydrogen storage materials is often above 300-500°C. Furthermore, hydrogen storage materials are often first fabricated on semiconductor devices before tritium absorption. This is extremely detrimental to temperature-sensitive semiconductors such as GaN, SiC, and GaAs, and can easily cause performance degradation or even damage. Currently, commonly used hydrogen storage materials have poor tritium storage performance at low temperatures. If tritium is absorbed at low temperatures to protect semiconductor devices, the resulting radioactive source will exhibit poor tritium absorption and storage performance, hindering the output power of the isotope battery. The hydrogen storage alloy film described in this solution can simultaneously meet the performance requirements of low-temperature tritium storage, high tritium storage density, high output power, and a high tritium release temperature threshold. The hydrogen storage alloy film prepared in this solution can absorb tritium at low temperatures of ≤100°C. It also has a high tritium storage density, and the tritium absorption capacity of the hydrogen storage alloy film can reach 6% (mass percentage).

[0015] Preferably, the hydrogen storage alloy film adsorbs and stores tritium in a temperature range of ≤100° C. Advantageously, the hydrogen storage alloy film achieves low-temperature tritium absorption, avoiding the technical problem of irreversible damage to the transducer device caused by conventional high-temperature tritium absorption processes during the preparation process, as well as the reduced hydrogen storage effect of the hydrogen storage alloy film at high temperatures.

[0016] Preferably, the first thin-film component further comprises a sheet-like first substrate, with the hydrogen storage alloy thin films disposed on both sides of the first substrate, each of which adsorbs tritium. Correspondingly, the second thin-film components are disposed on both sides of the first thin-film component. Simultaneously incorporating two tritium sources and a second thin-film component for converting energy into electricity within the same power generation unit can further improve power generation efficiency and increase the output power of the isotope battery.

[0017] Preferably, the first thin film member has a first extension with a first opening; the third thin film member has a second extension with a second opening; the first and second extensions extend outward from corresponding positions on opposite side edges of the second thin film member in opposite directions; the first opening of each power-generating unit is used to mount a positive conductive post; and the second opening of each power-generating unit is used to mount a negative conductive post. This solution has the advantage of conveniently connecting the positive and negative poles of each power-generating unit, facilitating the collection and unified output of the current generated by each unit.

[0018] Preferably, the system further includes a mounting base, with the positive and negative conductive posts pre-installed on the bottom of the mounting base; the first opening and the second opening of each power-generating unit are respectively sleeved onto the corresponding positive and negative conductive posts. This solution has the advantage of facilitating the positioning and installation of each power-generating unit. After each power-generating unit is prepared, each first opening is sleeved onto the positive conductive post, while each second opening is sleeved onto the negative conductive post, thereby achieving the positioning and installation of each power-generating unit.

[0019] Preferably, the second thin-film component includes a first transducer layer and a second transducer layer, with the first transducer layer positioned between the first and second transducer layers; the first transducer layer comprises a P-type semiconductor, and the second transducer layer comprises an N-type semiconductor. The use of P-type and N-type semiconductors in the second thin-film component helps improve charge collection efficiency and current output capacity, thereby enhancing the output power and performance of the isotope battery. This helps form a built-in electric field, endowing the isotope battery with certain rectifying properties, enabling current to flow in a specific direction, thereby improving the stability and reliability of the power output. Placing the N-type semiconductor away from the first thin-film component reduces direct exposure to radioactive particles, reducing the impact of radiation on its performance, extending the lifespan and stability of the isotope battery, and ensuring long-term, stable power output.

[0020] Preferably, within a single power-generating unit, the number of the third thin-film member is set to one, and the third thin-film member is located on a side of any second thin-film member away from the first thin-film member. Within two adjacent power-generating units, the third thin-film member of one unit is fixedly connected to the side of the adjacent unit not provided with the third thin-film member via a soldering layer. The soldering layer is a conductive single metal layer or alloy layer. The soldering layer can simultaneously perform fixing, electrical, and thermal conductivity functions, and is preferably a tin-bismuth solder paste.

[0021] Preferably, within the power generating unit, both sides of the first thin film member are respectively secured to the second thin film member and the third thin film member by soldering paste applied to the periphery. The solder paste is a single metal or an alloy. The solder paste can simultaneously perform fixing, electrical, and thermal conductivity functions, and is preferably a tin-bismuth solder paste.

[0022] Preferably, the overall shape of the thin film stacked compact isotope battery is a sheet structure with a certain thickness, and the thickness ranges from 1 to 15 mm.

[0023] The present invention has the following beneficial effects: The thin-film stacked compact isotope battery provided by the present invention can address the technical problem of low output power of existing compact radiovoltaic effect isotope batteries. The thin-film stacked compact isotope battery provided by the present invention utilizes a thin-film stack as its structure, reducing the isotope battery's volume while also increasing its output power, thereby facilitating the widespread use of radiovoltaic effect isotope batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to make the purpose, technical solutions and advantages of the invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings, in which:

[0025] Figure 1 Schematic diagram of the structure of the power generation unit according to an embodiment of the present invention.

[0026] Figure 2 Schematic diagram of the stacked structure of power generation units according to an embodiment of the present invention.

[0027] Figure 3 Schematic diagram of the planar structure of the first film member according to an embodiment of the present invention.

[0028] Figure 4 Schematic diagram of the planar structure of the third film member according to an embodiment of the present invention.

[0029] Explanation of the accompanying reference numerals: 1. Power generation unit; 11. First thin film component; 111. Hydrogen storage alloy thin film; 112. First extension portion; 113. First opening; 114. Solder paste; 12. Second thin film component; 121. First transducer layer; 122. Second transducer layer; 13. Third thin film component; 131. Second extension portion; 132. Second opening; 14. Welding layer; 15. Positive conductive column; 16. Negative conductive column; 17. Mounting substrate. DETAILED DESCRIPTION

[0030] To more clearly illustrate the objectives, technical solutions, and advantages of the embodiments of the present invention, the following will provide a detailed and complete description of the technical solutions in the embodiments of the present invention, with reference to the accompanying drawings. It should be noted that the same reference numerals and letters in the drawings represent similar components. Once a component is defined in one drawing, the definition and explanation will not be repeated in subsequent drawings.

[0031] The present invention can be applied to the field of isotope batteries, especially the field of miniaturized and compact isotope batteries, and solves the technical problem of low output power of existing compact radiovoltaic effect isotope batteries.

[0032] In order to further illustrate the isotope battery structure of the present invention, the present invention discloses the following embodiments.

[0033] Example 1, please refer to Figure 1 This embodiment provides a thin film stacked compact isotope battery, comprising at least two sequentially stacked power generation units 1; the power generation unit 1 comprises:

[0034] The first thin film member 11 is capable of generating radioactive particles and serves as the positive terminal of the power generation unit 1;

[0035] The second film element 12 is used to receive the radioactive particles generated by the first film element 11 and convert them into electricity;

[0036] The third thin film member 13 is used as the negative terminal of the power generation unit 1;

[0037] The second film member 12 is located between the first film member 11 and the third film member 13 .

[0038] The use of thin film stacking as the structure of the compact isotope battery can reduce the volume of the isotope battery. At the same time, the stacking of multiple power generation units 1 can increase the output power of the existing compact radiovoltaic effect isotope battery, which is conducive to the promotion and use of radiovoltaic effect isotope batteries.

[0039] Specifically, the number of the second film member 12 or the third film member 13 is set to one or two.

[0040] When there is one second film member 12, there is also one third film member 13. When there are two second film members 12, there are either one or two third film members 13. If there is one third film member 13, it is located on one side of either second film member 12. If there are two third film members 13, they are located on the outer sides of both second film members 12, away from the first film member 11.

[0041] Specifically, in this embodiment, the thickness of the first film member 11 is ≤200 μm, the thickness of the second film member 12 is ≤500 μm, and the thickness of the third film member 13 is ≤200 μm.

[0042] The thin-film stack compact isotope battery of this embodiment can achieve an output power of 1 to 40 μW, an output voltage range of 1.3 to 1.5 V, and an output current range of 0.7 to 26 mA. The output power, output voltage, and output current are related to the number of power-generating units 1 : a greater number of power-generating units 1 results in greater output power, output voltage, and output current.

[0043] Embodiment 2, based on embodiment 1, the first film member comprises a hydrogen storage alloy film, and the hydrogen storage alloy film adsorbs tritium;

[0044] The element composition of the hydrogen storage alloy film is Ti a Zr b V c Nb d Ni e M f ;

[0045] Wherein, M is one of Mg, Al, Cr, Mn, Fe, Co, and Mo;

[0046] Among them, the subscripts a, b, c, d, e, and f refer to the proportion of the number of atoms of the corresponding elements in the hydrogen storage alloy film, and the range of the proportion of each element is: 0.1≤a≤0.35, 0.1≤b≤0.35, 0.1≤c≤0.25, 0.1≤d≤0.35,

[0047] 0.05≤e≤0.3, 0.05≤f≤0.3, and a+b+c+d+e+f=1.

[0048] Specifically, the hydrogen storage alloy film absorbs and stores tritium at a temperature range of ≤100°C. This advantage lies in its ability to absorb tritium at low or even room temperature, avoiding the technical issues of irreversible damage to the transducer device caused by conventional high-temperature tritium absorption processes during the preparation process, as well as the reduced hydrogen storage efficiency of the hydrogen storage alloy film at high temperatures.

[0049] Specifically, the tritium release temperature of the hydrogen storage alloy film is ≥200°C.

[0050] Specifically, in this embodiment, the thickness of the hydrogen storage alloy film is ≤100 μm;

[0051] Specifically, in this embodiment, as a preferred solution for further reducing the thickness of the first thin film member, the thickness of the hydrogen storage alloy thin film is ≤100 μm;

[0052] Specifically, in this embodiment, as a preferred solution for further reducing the thickness of the first thin film member, the thickness of the hydrogen storage alloy thin film is in the range of 1.5 to 3 μm.

[0053] The output power of compact radiovoltaic isotope batteries also depends on the performance of the radioactive source. In existing technologies, the adsorption temperature of tritium gas by hydrogen storage materials is often between 300°C and 700°C. Furthermore, hydrogen storage materials are often first fabricated on semiconductor devices before tritium absorption. This is extremely detrimental to temperature-sensitive semiconductors such as GaN, SiC, and GaAs, and can easily lead to performance degradation or even damage. Currently, commonly used hydrogen storage materials have poor tritium storage performance at low temperatures. If tritium is absorbed at low temperatures to protect semiconductor devices, the resulting radioactive source will exhibit poor tritium absorption and storage, hindering the output power of the isotope battery. When isotope batteries are stacked and packaged, the process temperature is typically above 200°C. Therefore, it is necessary to ensure that the radioactive source does not release significant tritium gas below 200°C after tritium storage. The hydrogen storage alloy film in this scheme can simultaneously meet the performance indicators of low-temperature tritium storage, high tritium storage density, high output power and high tritium release temperature threshold. The hydrogen storage alloy film prepared by this scheme can absorb tritium in a low-temperature environment of ≤100°C. It also has a high tritium storage density, and the tritium absorption capacity of the hydrogen storage alloy film can reach 6%.

[0054] (mass percentage) The tritium release temperature of the hydrogen storage alloy film is above 200° C., thereby avoiding the problem of tritium gas release caused by high temperature during the isotope battery integration and packaging process.

[0055] In detail, the hydrogen storage alloy film of this embodiment has the following technical effects:

[0056] 1. Effectively solves the problem of irreversible damage to semiconductor devices caused by traditional high-temperature tritium absorption processes. The present invention utilizes the characteristics of a multi-principal alloy with a specific composition to absorb hydrogen at low temperatures, effectively avoiding high-temperature damage to semiconductor transducer devices.

[0057] 2. The hydrogen storage alloy film prepared by the present invention has a high tritium storage density. Based on the high entropy effect, the present invention effectively enhances the affinity of hydrogen in the multi-principal element alloy, enabling the prepared hydrogen storage alloy film to absorb up to 6% tritium by mass. Furthermore, the hydrogen storage alloy film has a high transmittance for radiation energy, effectively reducing the film's self-absorption of tritium radiation energy, ensuring the output power of the radiation source and, in turn, the power output of the isotope battery, facilitating its widespread application.

[0058] 3. The tritium storage material film prepared based on the present invention has a high tritium release temperature. By introducing high negative enthalpy elements such as Ti and Zr (Ti: -125kJ / mol H2, Zr: -165kJ / mol H2) and combining it with rapid annealing and ordering treatment, the tritium release temperature is raised to above 200°C, avoiding the problem of tritium gas release caused by high temperature during the isotope battery integration and packaging process.

[0059] The following is a description of the principle by which the hydrogen storage alloy film in this solution can absorb tritium at low temperature:

[0060] The various elements of the hydrogen storage alloy film have a large amount of configurational entropy, severe lattice distortion and high phase stability, and have unique crystal structure, chemical complexity and energy band characteristics, which are conducive to the absorption of tritium atoms at lower temperatures. Specifically,

[0061] (1) The hydrogen storage alloy film contains a large number of atoms of different sizes and different electronic structures, which increases the lattice distortion, provides a large number of non-equivalent tritium adsorption sites, reduces the energy barrier for tritium diffusion between metals, and enables tritium atoms to diffuse rapidly and penetrate into the alloy even at low temperatures.

[0062] (2) The hydrogen storage alloy film has a high density of dislocations, grain boundaries or vacancies, which are natural "tritium traps" and are conducive to the stable adsorption and low-temperature storage of tritium.

[0063] (3) The electronic structure effects and the intermixing of multiple transition metal d orbitals in the hydrogen storage alloy film change the chemical affinity of the alloy for tritium. By mixing elements with different hydrogen affinities, such as those with negative binding energies that readily react with hydrogen (such as Mg, Ti, or La) and elements with positive binding energies that do not react with hydrogen (such as Ni or Fe), the dehydrogenation enthalpy is reduced and the entropy is increased, thereby lowering the minimum tritium storage temperature.

[0064] The following is a principle explanation of how the hydrogen storage alloy film in this solution can effectively reduce the self-absorption effect of the film on tritium radiation energy:

[0065] Because the hydrogen storage alloy film has a non-periodic crystal structure, high configurational entropy, multiple localized adsorption sites, and tunable tritium-metal bonding energy, it essentially breaks the single diffusion and capture channel of tritium in the crystal lattice, thereby effectively reducing the self-absorption effect of tritium. Specifically,

[0066] (1) The hydrogen storage alloy film contains multiple main elements, resulting in a highly heterogeneous local environment in the lattice, with significant differences in atomic radius, valence electron structure, electronegativity, etc. After entering the alloy, tritium atoms encounter an uneven distribution of potential wells rather than a few strong traps. This prevents tritium atoms from concentrating on a certain type of site, thereby weakening self-absorption behavior.

[0067] (2) The lattice distortion of the hydrogen storage alloy film breaks the regular lattice trap structure in which tritium atoms are easily retained. The deformed lattice structure can inhibit the stable capture of tritium in dislocations or vacancies, thereby reducing the trap depth.

[0068] (3) After tritium atoms diffuse in traditional alloys, they tend to aggregate and form tritium clusters or bubbles due to the periodic arrangement of the lattice. However, the disordered atomic arrangement and complex spatial potential field in the hydrogen storage alloy film are necessary conditions for destroying the formation of tritium atoms, making it difficult for tritium to accumulate locally and form stable self-absorption zones.

[0069] (4) The defect migration path in high-entropy alloys is complex, and tritium atoms are more likely to escape from the trap during the migration process, reducing the effectiveness of the self-absorption trap.

[0070] In Example 3, based on Example 2, the hydrogen storage alloy thin film is prepared using one of magnetron sputtering, thermal deposition, laser deposition, electron beam deposition, chemical vapor deposition, electroplating, electroless plating, pulsed laser deposition, and MOCVD. Preferably, the hydrogen storage alloy thin film is prepared using magnetron sputtering deposition, and at least one target material is provided for preparing the hydrogen storage alloy thin film, and the target material is disposed at the cathode.

[0071] Example 4, based on Example 2, preferably, the hydrogen storage alloy film is prepared by magnetron sputtering deposition, and at least two target materials are provided for preparing the hydrogen storage alloy film, and each target material is provided at the cathode.

[0072] In Example 5, based on Example 2, the first thin-film component further comprises a sheet-like first substrate, with the hydrogen storage alloy thin films disposed on both sides of the first substrate, each of which adsorbs tritium. Correspondingly, the second thin-film components are disposed on both sides of the first thin-film component. By simultaneously incorporating two tritium sources and a second thin-film component for converting energy into electricity into a single power generation unit, power generation efficiency can be further improved, thereby increasing the output power of the isotope battery.

[0073] Specifically, in this embodiment, the surface roughness of the first substrate is ≤100 nm, and the substrate material is diamond or other homologous materials.

[0074] The technical solution of this embodiment is based on Example 4 and provides two preparation examples:

[0075] Preparation Example 1:

[0076] The first substrate has dimensions of 10 mm (length) × 10 mm (width) × 0.2 mm (thickness), is made of diamond, and has a roughness of 50 nm. Two target materials are provided: TiZrVNb and NiMn. The preparation method is as follows:

[0077] First, the first substrate is cleaned with alcohol ultrasonic cleaning and then blown dry, and then plasma cleaning is used to obtain the substrate surface with the best cleanliness. Then, the magnetron sputtering method is used to prepare the element composition of Ti on the surface of the first substrate.a Zr b V c Nb d Ni e M f A hydrogen storage alloy film, wherein a=b=c=d=x, e=f=y, M is Mn, and the aforementioned elemental composition can also be expressed as:

[0078] (TiZrVNb) x (NiMn) y , where 0.1≤x≤0.2, 0.1≤y≤0.3, and 4x+2y=1. In a specific implementation, by changing factors such as sputtering power, sputtering temperature, sputtering pressure, and sputtering time during magnetron sputtering, the ratio of x and y is adjusted to conform to theoretical calculations, and hydrogen storage alloy films of different thicknesses are prepared as needed.

[0079] Preferably, x=0.2, y=0.1, then the elemental composition is (TiZrVNb) 0.2 (NiMn) 0.1 The hydrogen storage alloy film composed of this element is placed in a vacuum of 5×10 -4 The device was heated to 50±10°C in a vacuum environment below 1.5 kPa, then tritium gas was introduced to 5 kPa to absorb tritium until saturation, resulting in a first thin film element with a thickness of 1.5 μm and a tritium absorption ratio of H / M = 1.5. This first thin film element was used to fabricate a power-generating unit, and IV testing of the resulting unit revealed a 35% increase in output power compared to a first thin film element fabricated from pure titanium film, and a 15% increase in output power compared to a first thin film element fabricated from the alloy TiZrVNbNi.

[0080] Preparation Example 2:

[0081] The first substrate has dimensions of 15 mm (length) × 15 mm (width) × 0.3 mm (thickness), is made of SiC, and has a roughness of 40 nm. Two target materials are provided: TiZrVNbNi and Al. The preparation method is as follows:

[0082] First, the first substrate is cleaned with alcohol ultrasonic cleaning and then blown dry, and then plasma cleaning is used to obtain the substrate surface with the best cleanliness. Then, the magnetron sputtering method is used to prepare the element composition of Ti on the surface of the first substrate. a Zr b V c Nb d Ni e M fA hydrogen storage alloy film, wherein a=b=c=d=e=k, M is Al, and the aforementioned elemental composition can also be expressed as: (TiZrVNbNi) k Al f , where 0.15≤k≤0.19, 0.05≤f≤0.25, and 5k+f=1. In a specific implementation, the ratio of k and f is adjusted to conform to theoretical calculations by changing factors such as sputtering power, sputtering temperature, sputtering pressure, and sputtering time during magnetron sputtering, and hydrogen storage alloy films of different thicknesses are prepared as needed.

[0083] Preferably, k = 0.16, f = 0.1, then the elemental composition is (TiZrVNbNi) 0.16 Al 0.2 The hydrogen storage alloy film composed of this element is placed in a vacuum of 1×10 -4 The device was heated to 70±10°C in a vacuum environment below 1.5 kPa, then tritium gas was introduced to 5 kPa to absorb tritium until saturation, resulting in a first thin film element with a thickness of 10 μm and a tritium absorption ratio of H / M = 1.7. This first thin film element was used to fabricate a power-generating unit, and IV testing of the resulting unit revealed a 45% increase in output power compared to a first thin film element fabricated from pure titanium film, and a 27% increase in output power compared to a first thin film element fabricated from the alloy TiZrVNbNi.

[0084] Preparation Example 3:

[0085] The first substrate has dimensions of 10 mm (length) × 10 mm (width) × 1 mm (thickness), is made of SiC, and has a roughness of 50 nm. Two target materials are provided: TiZrVNb and NiCr. The preparation method is as follows:

[0086] First, the first substrate is cleaned with alcohol ultrasonic cleaning and then blown dry, and then plasma cleaning is used to obtain the substrate surface with the best cleanliness. Then, the magnetron sputtering method is used to prepare the element composition of Ti on the surface of the first substrate. a Zr b V c Nb d Ni e M f A hydrogen storage alloy film, wherein a=b=c=d=x', e=f=y', M is Cr, and the aforementioned elemental composition can also be expressed as: (TiZrVNb) x’ (NiCr) y’, where x' is 0.1, 0.15, and 0.2, and y' is 0.3, 0.2, and 0.1, respectively. In the specific implementation, by changing the sputtering power, sputtering temperature, sputtering pressure, sputtering time and other factors in the magnetron sputtering process, (TiZrVNb) x’ (NiCr) y’ Meet the required proportions.

[0087] The prepared (TiZrVNb) 0.1 (NiCr) 0.3 、(TiZrVNb) 0.15 (NiCr) 0.2 、(TiZrVNb) 0.2 (NiCr) 0.1 The hydrogen storage alloy film composed of three groups of elements was placed in a vacuum of 8×10 -4 The device was heated to 80±10°C in a vacuum environment below 6 kPa, and tritium gas was then introduced to 6 kPa to absorb tritium until saturation. This resulted in three sets of thin film components, all 2 μm thick, with tritium absorption ratios of H / M = 1.4, 1.6, and 1.5, respectively. The first thin film component with the highest tritium absorption ratio was used to fabricate a power-generating unit. IV testing of the resulting power-generating unit revealed a 40% increase in output power compared to a power-generating unit fabricated using a pure titanium film, and a 31% increase in output power compared to a power-generating unit fabricated using a TiZrVNbNi alloy.

[0088] Preparation Example 4:

[0089] The first substrate has dimensions of 10 mm (length) × 10 mm (width) × 4 mm (thickness), is made of Si, and has a roughness of 30 nm. Three target materials are provided: Ti, ZrNb, and VNiFe. The preparation method is as follows:

[0090] First, the first substrate is cleaned with alcohol ultrasonic cleaning and then blown dry, and then plasma cleaning is used to obtain the substrate surface with the best cleanliness. Then, the magnetron sputtering method is used to prepare the element composition of Ti on the surface of the first substrate. a Zr b V c Nb d Ni e M f A hydrogen storage alloy film, wherein b=d=m, c=e=f=n, M is Fe, and the above element composition can also be recorded as: Ti a (ZrNb) m (VNiFe) n, where 0.1≤a≤0.35, 0.2≤m≤0.35, 0.05≤n≤0.25 and x+2y+3z=1. In the specific implementation, by changing the sputtering power, sputtering temperature, sputtering pressure, sputtering time and other factors in the magnetron sputtering process, Ti a (ZrNb) m (VNiFe) n Meet the required proportions.

[0091] Preferably, a=0.3, m=0.2, n=0.1, then the element composition is Ti 0.3 (ZrNb) 0.2 (VNiFe) 0.1 The hydrogen storage alloy film composed of this element is placed in a vacuum of 2×10 -4 The device was heated to 90±10°C in a vacuum environment below 1000 Pa, then tritium gas was introduced to 5 kPa to absorb tritium until saturation, resulting in a first thin film element with a thickness of 2.5 μm and a tritium absorption ratio of H / M = 1.7. The resulting first thin film element was used to fabricate a power-generating unit, and IV testing of the resulting unit revealed a 48% increase in output power compared to a first thin film element fabricated from pure titanium film, and a 33% increase in output power compared to a first thin film element fabricated from the alloy TiZrVNbNi.

[0092] Preparation Example 5:

[0093] The first substrate has a size of 20mm (length) × 20mm (width) × 2mm (thickness), is made of diamond, and has a roughness of 35nm. There are three types of target materials: TiZrVNbNi, Co, and Mo. Their preparation methods are as follows:

[0094] First, the first substrate is cleaned with alcohol ultrasonic cleaning and then blown dry, and then plasma cleaning is used to obtain the substrate surface with the best cleanliness. Then, the magnetron sputtering method is used to prepare the element composition of Ti on the surface of the first substrate. a Zr b V c Nb d Ni e M f A hydrogen storage alloy film, wherein a=b=d=c=e=f, M is Co or Mo, and the aforementioned elemental composition can also be recorded as: TiZrNbVNiCo or TiZrNbVNiMo. In a specific implementation, by changing factors such as sputtering power, sputtering temperature, sputtering pressure, and sputtering time during the magnetron sputtering process, each element in TiZrNbVNiCo or TiZrNbVNiMo is made to be approximately equimolar.

[0095] The hydrogen storage alloy films composed of TiZrNbVNiCo and TiZrNbVNiMo were placed in a vacuum of 3×10 -4 The device was heated to 80±10°C in a vacuum environment below 1.5 kPa, then tritium gas was introduced to 5 kPa to absorb tritium until saturation, resulting in a first thin film component with a thickness of 3 μm and tritium absorption ratios of H / M = 1.7 and 1.6, respectively. The first thin film component with the highest tritium absorption ratio was used to fabricate a power-generating unit, and IV testing of the resulting unit revealed a 46% increase in output power compared to a first thin film component fabricated from pure titanium film, and a 28% increase in output power compared to a first thin film component fabricated from the alloy TiZrVNbNi.

[0096] Example 6, based on Example 5, the power generation unit is prepared using the following preparation method:

[0097] The power generation unit is prepared by the following preparation method:

[0098] S1. Coating a hydrogen storage alloy material on both sides of the first substrate so that both sides of the first substrate have the hydrogen storage alloy film, and performing laser annealing treatment;

[0099] S2, placing the device after laser annealing in step S1 in a vacuum environment with a temperature range of ≤100° C.; and introducing tritium gas so that the hydrogen storage alloy film on each side is adsorbed with tritium, thereby obtaining the first thin film component;

[0100] S3, fixing a second film member on both sides of the first film member;

[0101] S4. Fix a third film member on a side of any one of the second film members away from the first film member to obtain the power generation unit.

[0102] Compared with the technical solution in the prior art that first sputters the radioactive source onto the semiconductor device and then absorbs tritium at high temperature, which may cause structural damage to the semiconductor device, the advantage of this technical solution is that it realizes the separate preparation and installation of the radioactive source and the transducer device, avoiding the irreversible damage to the transducer device caused by the traditional high-temperature tritium absorption process during the preparation process. At the same time, it also realizes the absorption of tritium by the hydrogen storage alloy film in a low-temperature vacuum environment of ≤100°C, effectively protecting the structural integrity of the first substrate. The two work together to effectively solve the disadvantages of the prior art.

[0103] In this embodiment, in step S1, hydrogen storage alloy material is coated on both sides of the first substrate respectively, using the following steps:

[0104] S1.1. Clean the surface of the first substrate by ultrasonic cleaning with acetone, alcohol, and deionized water in sequence;

[0105] S1.2. Using a magnetron sputtering method, in an inert gas environment, a hydrogen storage alloy material is used as a target material and deposited on the surface of a first substrate to obtain a first substrate coated with a hydrogen storage alloy film.

[0106] Specifically, in step S1.1, the cleaning time of each cleaning agent is 10 to 20 minutes.

[0107] Specifically, in step S1.2, the sputtering temperature is ≤150°C, the coating pressure is <8Pa, and the power is controlled to be ≤1000W.

[0108] As a specific implementation of step S1, multi-target deposition is adopted when performing magnetron sputtering.

[0109] Specifically, the material of the first substrate is a metal material, including but not limited to steel foil, copper sheet, aluminum sheet, molybdenum sheet, etc.

[0110] Specifically, the material of the first substrate may also be a non-metallic material, including but not limited to a ceramic sheet.

[0111] Example 7, based on Example 1, please refer to Figures 2 to 4 The first thin film member 11 has a first extension 112, which defines a first opening 113. The third thin film member 13 has a second extension 131, which defines a second opening 132. The first extension 112 and the second extension 131 extend outward in opposite directions from corresponding positions on opposite side edges of the second thin film member 12. The first opening 113 of each power generating unit 1 is used to mount a positive conductive post 15, while the second opening 132 of each power generating unit 1 is used to mount a negative conductive post 16. This solution has the advantage of conveniently connecting the positive and negative electrodes of each power generating unit 1, facilitating the collection and unified output of the current generated by each power generating unit 1.

[0112] Specifically, both sides of the third thin film member 13 are plated with gold films, and both sides of the second extension portion 131 are also plated with gold films.

[0113] Specifically, both sides of the first extension portion 112 of the first film member 11 are plated with gold films.

[0114] Example 8, based on Example 7, please refer to Figure 2, further comprising a mounting substrate 17, the positive conductive column 15 and the negative conductive column 16 being pre-installed on the bottom of the mounting substrate 17; the first opening 113 and the second opening 132 of each power generating unit 1 are respectively sleeved on the corresponding positive conductive column 15 and negative conductive column 16. The advantage of this solution is that it facilitates the positioning and installation of each power generating unit 1. After each power generating unit 1 is prepared, each first opening 113 is sleeved on the positive conductive column 15, and each second opening 132 is sleeved on the negative conductive column 16, thereby achieving the positioning and installation of each power generating unit 1.

[0115] Example 9, based on any one of Examples 1 to 8, please refer to Figure 1 The second thin film member 12 includes a first transducer layer 121 and a second transducer layer 122. The first transducer layer 121 is located between the first thin film member 11 and the second transducer layer 122. The first transducer layer 121 includes a P-type semiconductor, and the second transducer layer 122 includes an N-type semiconductor. Specifically, the material of the first transducer layer or the second transducer layer is one of gallium arsenide, gallium nitride, silicon carbide, and diamond.

[0116] In this way, the P-type semiconductor is located on the positive electrode side and the N-type semiconductor is located on the negative electrode side, ensuring a smooth current flow. Specifically, the majority carriers in the P-type semiconductor are holes, while the majority carriers in the N-type semiconductor are electrons. When radioactive particles are generated by the first thin-film element, the energy of the radioactive particles is transferred to electrons in the P-type semiconductor, causing them to transition from the valence band to the conduction band, generating a large number of non-equilibrium carriers (electron-hole pairs). Because the P-type semiconductor is closer to the radiation source, it absorbs the radiation energy more efficiently and generates carriers. Under the influence of the built-in electric field formed by the PN junction, these carriers move holes into the P-type semiconductor and electrons into the N-type semiconductor, forming a directional current and converting the radiation energy into electricity. Utilizing the different carrier properties of the two semiconductors helps improve charge collection efficiency and current output capacity. It also facilitates the generation of a higher carrier concentration gradient in the P-type semiconductor. Because the P-type semiconductor is closer to the radiation source, it absorbs more radiation energy and has a high carrier generation rate, while the N-type semiconductor is farther away from the radiation source and has a low carrier generation rate, resulting in a difference in carrier concentration on both sides of the PN junction. This concentration gradient will promote further diffusion of carriers, and together with the drift effect of the built-in electric field, it will enable more carriers to participate in the conduction process, improve the energy conversion efficiency, and be able to more fully convert the energy of the radioactive source into electrical energy, thereby improving the output power and performance of the isotope battery.

[0117] The second thin-film element, constructed by closely contacting a P-type semiconductor with an N-type semiconductor, forms a PN junction. This junction generates a built-in electric field directed from the N region to the P region. This built-in electric field is crucial for separating generated electron-hole pairs. When a large number of carriers are generated in the P-type semiconductor near a radiation source, the built-in electric field rapidly pushes the electrons and holes toward the N-type and P-type semiconductors, respectively, preventing them from recombination. This improves carrier utilization, facilitates stable electromotive force generation, and promotes continuous current output. Furthermore, the presence of the built-in electric field imparts a certain rectifying property to the isotope battery, enabling current to flow in a specific direction, thereby improving the stability and reliability of the power output.

[0118] Keeping N-type semiconductors away from radiation sources can reduce direct radiation exposure. Radioactive particles can cause radiation damage to semiconductor materials, such as creating lattice defects and altering the material's electrical properties. N-type semiconductors primarily collect electrons and conduct current during the energy conversion process. Their performance stability is crucial to the overall performance of the battery. Keeping N-type semiconductors away from radiation sources can reduce the impact of radiation on their performance, extend the lifespan and stability of the isotope battery, and ensure long-term, stable power output.

[0119] Example 10, based on Example 5 and Example 8, please refer to Figure 1 In the same power-generating unit 1, the number of the third thin film member 13 is set to one, and the third thin film member 13 is located on the side of any second thin film member 12 away from the first thin film member 11. In two adjacent power-generating units 1, the third thin film member 13 of one power-generating unit 1 is fixedly connected to the side of the adjacent power-generating unit 1 not provided with the third thin film member 13 by a welding layer 14. The welding layer 14 is a conductive single metal layer or alloy layer. The welding layer 14 can simultaneously perform the functions of fixation, electrical conduction, and thermal conductivity, and is preferably a tin-bismuth solder paste 114. Then, due to the conductive function of the welding layer 14, the various power-generating units 1 are in a parallel state, which can achieve the function of reducing voltage while increasing current, so that it can be applied to the current (0.7-26mA) and voltage (1.3-1.5V) requirements of the power-consuming objects, such as crankshaft position sensors, acceleration gyroscope sensors, etc.

[0120] Another advantage of this arrangement is that the internal structure of each power-generating unit 1 is transformed from an independent power-generating unit 1 into an integral structure, forming a cyclic stacking structure of the third film component 13 - the second film component 12 - the first film component 11 - the second film component 12 - the third film component 13 - the second film component 12 - ..., so that the current generated by each transducer device can be collected and flowed out of the common positive and negative electrodes, which can save the number of first film components 11 (positive electrode) and third film components 13 (negative electrode), further reduce the volume of the isotope battery, and at the same time ensure that the output power is not reduced.

[0121] like Figure 2 As shown, based on Example 5 and Example 8 and this embodiment, the stacking method of each power generating unit 1 includes the following steps (taking the third film member 13 at the top of the power generating unit 1 as an example):

[0122] D1. Fix the positive conductive column 15 and the negative conductive column 16 at the bottom of the mounting substrate 17 according to the designed distance, and apply a layer of tin-bismuth solder paste 114 to the area between the positive conductive column 15 and the negative conductive column 16;

[0123] D2. Prepare a semi-finished power-generating unit 1 excluding the third film member 13. Align the first opening 113 of the first film member 11 of the semi-finished power-generating unit 1 with the positive conductive post 15 and sleeve the semi-finished power-generating unit 1 onto the positive conductive post 15. Lower the semi-finished power-generating unit 1 onto the bottom of the mounting substrate 17 coated with tin-bismuth solder paste 114, ensuring that the semi-finished power-generating unit 1 is tightly attached to the mounting substrate 17.

[0124] D3, applying a layer of tin-bismuth solder paste 114 to the side of the semi-finished power generating unit 1 away from the mounting substrate 17 in step D2;

[0125] D4. Align the second opening 132 of the third film member 13 with the negative electrode conductive post 16 and sleeve the third film member 13 onto the negative electrode conductive post 16, extending downward to the semi-finished power-generating unit 1 coated with the tin-bismuth solder paste 114, thereby completing the stacking of one of the power-generating units 1.

[0126] D5, coating a layer of tin-bismuth solder paste 114 on the top of the third film member 13 of the power generating unit 1 stacked in step D4;

[0127] D6. Repeat steps D2 to D5 to stack multiple power-generating units 1, and reflow-curing them at a specific temperature (e.g., 182 degrees Celsius) to ensure that the components are firmly fixed.

[0128] D7. Through wire bonding and parallel sealing, the electrical interconnection and sealing of the isotope battery are achieved, and a compact isotope battery with thin film stacking is obtained.

[0129] Example 11, based on Example 1, please refer to Figure 2 and Figure 4 Inside the power generating unit 1, both sides of the first thin film member 11 are soldered to the second thin film member 12 and the third thin film member 13 using solder paste 114 applied to the periphery. The solder paste 114 is made of a single metal or an alloy. The solder paste 114 can simultaneously perform fixing, electrical, and thermal conductivity functions, and is preferably a tin-bismuth solder paste 114.

[0130] Taking the first film component 11 and the second film component 12 as an example, the tin-bismuth solder paste 114 is first applied to the four sides of the first film component 11, and then the second film component 12 is tightly fitted to the first film component 11, and then reflow cured at 182 degrees Celsius to achieve a fixed connection between the first film component 11 and the second film component 12.

[0131] In Example 12, based on any of the above examples, the thin-film stacked compact isotope battery has an overall sheet-like structure with a thickness ranging from 1 to 15 mm. Specifically, the number of power-generating units stacked within the thin-film stacked compact isotope battery ranges from 2 to 20.

[0132] In the description of the present invention, it should be noted that the orientations or positional relationships represented by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, or are the conventional placement orientations or positional relationships of the invention product when in use. The use of these terms is merely to facilitate the description of the present invention and simplify the description, and does not mean that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish different components or steps, and are not used to indicate or imply relative importance. In addition, the terms "horizontal", "vertical", etc. do not mean that the components must be absolutely horizontal or suspended, but rather allow for a certain angle of inclination. For example, "horizontal" only means that its direction is closer to a horizontal state relative to "vertical", rather than requiring that the structure must be completely horizontal. In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "installed", "connected", "connected", etc. should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be a communication between two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0133] It should also be noted that the present invention is illustrated by means of several embodiments. Those skilled in the art should understand that, without departing from the core spirit and scope of the present invention, various modifications, adjustments or equivalent replacements may be made to the features in these embodiments. According to the guiding ideology of the present invention, technicians can make appropriate adjustments to the embodiments according to specific application scenarios and materials without exceeding the scope of protection of the present invention. It should be pointed out that the embodiments described in the present invention are only a part of the many implementation methods of the present invention, not all of them. The various components of the embodiments of the present invention shown in the accompanying drawings can be arranged and designed in different configurations according to actual needs. Therefore, the above detailed description of the embodiments shown in the accompanying drawings is not intended to limit the scope of protection of the present invention, but is only an elaboration of some embodiments of the present invention. The scope of protection of the present invention should not be limited to the specific embodiments disclosed herein. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.

Claims

1. A thin film stacked compact isotope battery, characterized in that: It comprises at least two electricity generating units stacked in sequence; the electricity generating unit comprises, a first thin film member capable of generating radioactive particles and serving as a positive terminal of the power generation unit; The second film element is used to receive the radioactive particles generated by the first film element and convert them into electricity; a third thin film member, used as a negative terminal of the power generating unit; The second film member is located between the first film member and the third film member.

2. The thin film stacked compact isotope battery according to claim 1, characterized in that: The first film member includes a hydrogen storage alloy film, and the hydrogen storage alloy film adsorbs tritium; The element composition of the hydrogen storage alloy film is Ti a Zr b V c Nb d Ni e M f ; Wherein, M is one of Mg, Al, Cr, Mn, Fe, Co, and Mo; Among them, the subscripts a, b, c, d, e, and f refer to the proportion of the number of atoms of the corresponding elements in the hydrogen storage alloy film, and the range of the proportion of each element is: 0.1≤a≤0.35, 0.1≤b≤0.35, 0.1≤c≤0.25, 0.1≤d≤0.35, 0.05≤e≤0.3, 0.05≤f≤0.3, and a+b+c+d+e+f=1.

3. The thin film stacked compact isotope battery according to claim 2, characterized in that: The temperature range in which the hydrogen storage alloy film adsorbs and stores tritium is ≤100°C.

4. A thin film stacked compact isotope battery according to claim 2 or 3, characterized in that: The first film component further includes a sheet-shaped first substrate, with the hydrogen storage alloy film on both sides, and tritium adsorbed on each side of the hydrogen storage alloy film; correspondingly, the second film component is provided on both sides of the first film component.

5. The thin film stacked compact isotope battery according to claim 1, characterized in that: The first film member has a first extension portion, which is provided with a first opening; the third film member has a second extension portion, which is provided with a second opening; the first extension portion and the second extension portion extend outward in opposite directions from corresponding positions of opposite side edges of the second film member; the first opening of each power generating unit is used to install a positive conductive column; the second opening of each power generating unit is used to install a negative conductive column.

6. The thin film stacked compact isotope battery according to claim 1, characterized in that: It also includes a mounting substrate, the positive conductive column and the negative conductive column are pre-installed on the bottom of the mounting substrate respectively; the first opening and the second opening of each power generating unit are respectively sleeved on the corresponding positive conductive column and negative conductive column.

7. The thin film stacked compact isotope battery according to claim 1, characterized in that: The second thin film component includes a first transduction layer and a second transduction layer, wherein the first transduction layer is located between the first thin film component and the second transduction layer; the first transduction layer includes a P-type semiconductor, and the second transduction layer includes an N-type semiconductor.

8. The thin film stacked compact isotope battery according to claim 1, characterized in that: In the same power generating unit, the number of the third film components is set to one, and the third film component is located on the side of any one of the second film components away from the first film component; in two adjacent power generating units, the third film component of one power generating unit is fixedly connected to the side of the adjacent power generating unit where the third film component is not provided through a welding layer, and the welding layer is a single metal layer or alloy layer that can conduct electricity.

9. The thin film stacked compact isotope battery according to claim 1, characterized in that: Inside the power generation unit, two sides of the first film member are respectively fixed to the second film member and the third film member by welding through solder paste dotted around them, and the solder paste is a single metal or an alloy.

10. The thin film stacked compact isotope battery according to claim 1, characterized in that: The overall shape of the thin film stacked compact isotope battery is a sheet structure with a certain thickness, and the thickness ranges from 1 to 15 mm.

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