A review for nuclear batteries based on diamond

The nuclear battery has many advantages, including high energy density, stable performance, no manual intervention etc., which can be widely utilized in cases requiring long-term reliable power supply. Among them, the Radioisotope Thermoelectric Generators (RTG) is the earliest used and the most technically matured one, while betavoltaic battery is now commercialized. However, there are still some problems including self-absorption effect, low energy conversion efficiency and severe radiation damage which restrict the application of betavoltaic batteries. Additionally, for an actual nuclear battery, it should be noticed that the component and density of the source will be changed because the radiation source decays continually, which leads to the electrical performance decline. In this review, the major events in nuclear battery development are listed on a timeline, and the principles and applications of different types of nuclear batteries are also introduced. For betavoltaic battery, the existence of self-absorption effect is pointed out as an important scientific problem, and for batteries with 63Ni and TiT2 source, the time-related electrical properties are also obtained. This paper also pointed out that, fine and precise calculations are very crucial in the optimized designing processes for a particular structure of the practical nuclear battery. Finally, researching assumptions including combining the source and the energy converting material and the use of energy converting structures with heavier isotopes are presented, which are benefit to solve the self-absorption problem, rise the output power of the nuclear battery and reduce the influence of radiation damage.

As an important kind of energy source, radioisotope batteries are attracting more and more academic researchers and people from industry due to the high power density, long lifetime (equal to half life of the radioisotope source), outstanding reliability, without maintenance, miniaturization and wide application compared with traditional dry batteries, chemical batteries, fuel batteries and solar batteries. Based on the optimization of functional materials and energy conversion types, radioisotope batteries have been developed for more than 15 species since the first β battery invented by Henry Mosley in 1913. This review describes historical background and development, limitations of key techniques in radioisotope batteries. The radioisotope source loading methods and thermocouple materials of radioisotope thermoelectric generator (RTG), the semiconductor materials and energy conversion units of radiation voltaic isotope batteries (RVIB) are analysed in detail. After an introduction of the basic principles and design requirements of radioisotope batteries, we discuss the technical proposals of different energy conversions for radioisotope batteries. Then, the most recent experimental results for several configurations and experimental set-ups of radioisotope batteries are introduced detailedly, including static thermoelectric type radioisotope batteries, radiation voltaic effect radioisotope batteries, dynamic energy transformation radioisotope batteries and piezoelectric energy transformation radioisotope batteries. The figure for PCEs (Power Conversion Efficiencies) in different radioisotope batteries from 1913 to 2015 is first demonstrated in the end, which illustrates the PCEs of RTG, RVIB are close to 10% and DIPS (Dynamic Isotope Power System) is higher than 23%. Thus, the PCEs of radioisotope batteries will increase effectively if some various high efficient energy conversion types like RTG, RTPV (Radioisotope thermophotovoltaic) and RTIGs (Radioisotope Thermionic emission Generators) are assembled. In the future, four main trends for radioisotope batteries include the better safety and reliability, the higher output power and power matching, the micro/nano integration and module combination of battery structure, the production of radioisotope source. We believe that the research and application of radioisotope batteries will be much attractive with the break through of these aspects made by academic and industrial world.

Nuclear batteries have strategic applications and very high economic potential. One Important problem in application of nuclear betavoltaic battery is its low efficiency. Current efficiency of betavoltaic nuclear battery reaches only arround 2%. One aspect that can influence the efficiency of betavoltaic nuclear battery is the geometrical configuration of radioactive source. In this study we discuss the effect of geometrical configuration of radioactive source material to the radiation intensity in betavoltaic nuclear battery system. received by the detector. By obtaining the optimum configurations, the optimum usage of radioactive materials can be determined. Various geometrical configurations of radioactive source material are simulated. It is obtained that usage of radioactive source will be optimum for circular configuration.

A [formula omitted]-radioisotope battery based on betavoltaic and beta-photovoltaic dual effects

Demonstration of a Tritiated Nitroxide Nuclear Battery

A review of nuclear batteries

Nuclear batteries, a novel energy device in microelectromechanical systems (MEMS), have garnered significant attention from academia and industry due to their promising application prospects. They possess high energy density and reliable operation without human intervention and offer unique advantages in the case of long-term stable power supply. Among these, thermal conversion nuclear batteries (RTGs) represent the most mature technology and the earliest application, while betavoltaic nuclear batteries have entered commercialization. Challenges in betavoltaic nuclear batteries research include energy wastage due to the self-absorption effect of radioactive sources, low conversion efficiency, and significant radiation damage to transducer devices. These issues are attributable not only to the inherent properties of the radioactive source but also to the material and structural design of transducers. A 3D interface structure design scheme based on the wide bandgap semiconductor material GaN and the radioactive isotope 63Ni nuclear microbatteries is proposed. In the scheme, Geant4 and COMSOL Multiphysics were used to simulate the GaN-based betavoltaic nuclear battery of 63Ni source, and the PN junction 3D interface structure of the transducer was designed and optimized. The effects of the surface area, number of micropillars, thickness, and doping concentration of each region on the battery performance were analyzed. Results indicate that with P- and N- region thicknesses and doping concentrations at 0.1, 9.9 µm, 1 × 1018, and 1 × 1014 cm−3, respectively, the nuclear battery can achieve a conversion efficiency of 7.57%, a short-circuit current density of 0.3959 µA/cm2, an open-circuit voltage of 2.3074 V, and maximum output power of 0.7795 µW/cm2. In addition, discussion regarding the surface area and quantity of P-layer micropillars confirms the hypothesis that these variables are positively correlated with the output performance of the transducer.

The discovery and development of ultra-wide bandgap (UWBG) semiconductors is crucial to accelerate the adoption of renewable power sources. This necessitates an UWBG semiconductor that exhibits robust doping with high carrier mobility over a wide range of carrier concentrations. Here we demonstrate that epitaxial thin films of the perovskite oxide NdxSr1−xSnO3 (SSO) do exactly this. Nd is used as a donor to successfully modulate the carrier concentration over nearly two orders of magnitude, from 3.7 × 1018 cm−3 to 2.0 × 1020 cm−3. Despite being grown on lattice-mismatched substrates and thus having relatively high structural disorder, SSO films exhibited the highest room-temperature mobility, ~70 cm2 V−1 s−1, among all known UWBG semiconductors in the range of carrier concentrations studied. The phonon-limited mobility is calculated from first principles and supplemented with a model to treat ionized impurity and Kondo scattering. This produces excellent agreement with experiment over a wide range of temperatures and carrier concentrations, and predicts the room-temperature phonon-limited mobility to be 76–99 cm2 V−1 s−1 depending on carrier concentration. This work establishes a perovskite oxide as an emerging UWBG semiconductor candidate with potential for applications in power electronics.

Design and optimization of 90Sr–Si betavoltaic nuclear battery and its comparison with a direct charge nuclear battery based on 90Sr radioactive source

Betavoltaic (BV) batteries are regarded as appealing power sources due to their high energy densities and long lifetimes. However, the low efficiency and maximum output power density of conventional BV batteries due to the self-absorption effect of radioactive sources, which consist of separate beta-radioactive sources and semiconductor absorbers, limit their applications. In this work, we optimized and compared six 63NiO-related heterojunction nuclear batteries utilizing Monte Carlo software Geant4 and finite element analysis software COMSOL Multiphysics. The 63NiO-related heterojunction nuclear batteries integrate beta-radioactive sources and semiconductor absorbers to overcome the shortcomings of conventional BV batteries. Furthermore, we proposed a parallel connection structure utilizing graphene electrode layer to connect two 63NiO/GaP heterojunctions based on the optimal one from the six heterojunctions in order to maximize the maximum output power density. The total energy conversion efficiency is 2.68% and the maximum output power density is of the parallel connection nuclear battery. Finally, we investigated the time-related performance of the parallel connection structure nuclear battery within 200 years. It shows that the maximum output power density decreases from in the beginning to at 200 years.

A dual-effect nuclear battery based on the radio-voltaic and radioluminescence effect was developed, which has the ability to convert nuclear energy into electrical energy with two different modes. Performance-enhanced nuclear batteries are mainly based on the addition of ZnS:Cu radio-luminescent layer to Cd-109 X-ray radioactive source and GaAs radio-voltaic layer. In order to explore the response relationship between the mode of energy conversion and the electrical performance of nuclear battery, the physical model was established to research the deposition energy distribution by using Monte Carlo method. The addition of the radio-luminescent material increases the effective energy deposition of the X-rays and the optimized thickness of ZnS:Cu in such a dual-effect nuclear battery should be set to 560 μm. The current–voltage characteristic curves of the batteries before and after performance optimization were utilized to investigate the electrical properties. Through a comprehensive comparison of Cd-109 nuclear batteries with or without radio-luminescent layer, the simulated results are consistent with experimental results. The results indicate that the electrical performance of dual-effect nuclear battery is significantly higher than that of single radio-voltaic nuclear battery. Moreover, the energy conversion efficiency increases from 0.079% (single radio-voltaic nuclear battery) to 0.119% (dual-effect nuclear battery). The improved performance of the dual-effect nuclear battery provides potential applications for space-based autonomous remote sensors and continuous low-power generation technologies.

Nuclear energy emerges as a promising and environmentally friendly solution to counter the escalating levels of greenhouse gases resulting from excessive fossil fuel usage. Essential to harnessing this energy are nuclear batteries, devices designed to generate electric power by capturing the energy emitted during nuclear decay, including α or β particles and γ radiation. The allure of nuclear batteries lies in their potential for extended lifespan, high energy density, and adaptability in harsh environments where refueling or battery replacement may not be feasible. In this review, we narrow our focus to nuclear batteries utilizing non-thermal converters such as α- or β-voltaics, as well as those employing scintillation intermediates. Recent advancements in state-of-the-art direct radiation detectors and scintillators based on metal perovskite halides (MPHs) and chalcogenides (MCs) are compared to traditional detectors based on silicon and III-V materials, and scintillators based on inorganic lanthanide crystals. Notable achievements in MPH and MC detectors and scintillators, such as nano-Gy sensitivity, 100 photons/keV light yield, and radiation hardness, are highlighted. Additionally, limitations including energy conversion efficiency, power density, and shelf-life due to radiation damage in detectors and scintillators are discussed. Leveraging novel MPH and MC materials has the potential to propel nuclear batteries from their current size and power limitations to miniaturization, heightened efficiency, and increased power density. Furthermore, exploring niche applications for nuclear batteries beyond wireless sensors, low-power electronics, oil well monitoring, and medical fields presents enticing opportunities for future research and development.

In this work, a nuclear battery with a 14C source was developed to improve the electrical properties of betavoltaic batteries. The betavoltaic battery energy converters containing different semiconductors, such as Ga2O3, GaAs, GaN, GaP, Si, and SiC, were evaluated to convert the 14C radioisotope source energy into electrical energy. The electrical output properties of the betavoltaic battery were established through numerical calculation for two structures of the p-n junction and Schottky barrier (with Ag, Al, Au, Mo, Ni, Pd, and Pt as Schottky metals). The optimum thickness of the 14C radioisotope and its energy deposition distribution within the semiconductors were determined using the Monte Carlo method. In the betavoltaic battery with the p-n junction configuration, the optimized doping concentration yielded a maximum output power density and energy conversion efficiency of 20.97 μW·cm−2 and 7.20%, respectively, for the Ga2O3 semiconductor. In contrast, these parameters for the Pt-Si Schottky barrier betavoltaic were obtained at 1.34 μW·cm−2 and 0.46%, respectively, with the 20-nm thickness of the Pt Schottky metal layer and a doping concentration of 1015 cm−3. These findings are valuable and helpful for assembling reasonable betavoltaic batteries.

Nuclear power plants produce the largest amount of tritium. Tritium is a by-product of nuclear reactors. Currently, it can only be placed in sealed storage tanks. Radioactive waste can be used as a source of energy for radioisotope battery. Since isotope energy is continuously converted into electrical energy for a long period of time, it is considered an ideal choice for remote applications. The mechanism of current generation of nuclear batteries is similar to that of solar cells. The only difference is that the electron holes are generated from radiation, not from light. The novel technologies of betavoltaic batteries would make use of the synthetic strategy for TiO2 semiconductors and the radioactive wastes radiation sources (H-3) stored in INER (Institute of Nuclear Energy Research, Taiwan). The radioactive waste can become a source of energy for radioisotope generators. At first, this study evaluates the radiation shielding safety distance required for radioactivity used in a betavoltaic tritium battery. The technological innovation includes the experimental synthesis of TiO2 nanotube in a complete array and the use of TiO2 nanotube arrays (TNTAs) as the semiconductor inside radioisotope batteries. In this work, combining the technology of TiO2 synthesizing TiO2 nanotube arrays with liquid waste radiation sources (tritium, H-3), the betavoltaic tritium battery (Ni/H-3/TNTAs/Ti) have successfully created and analyzing the characteristics of betavoltaic battery. Durability was assessed using analytical parameters of betavoltaic batteries compared to lithium-ion batteries. Such betavoltaic batteries have practical advantages in tritium handling applications and long-term battery performance.

Nuclear energy is considered a suitable and eco-friendly alternative for combating the rising greenhouse gases in the atmosphere from excessive fossil fuel consumption. Betavoltaic battery is a form of nuclear technology that utilizes the decay energy of β-emitting radioisotopes to produce electrical power. Owing to its long shelf life, high specific energy density, and ability to work under extreme conditions, it has been a subject of considerable research attention in the past few years. Despite significant research on betavoltaic battery, several impediments to realizing high energy conversion efficiency and maximum power density have yet to be overcome. This Review Article comprehensively discusses the challenges and recent research progress of betavoltaic battery development. First, promising strategies for improving betavoltaic battery performance, theoretical principles, and equations for quantifying betavoltaic battery efficiency are discussed. Then a thorough overview of several β-radiation absorbing materials, such as traditional semiconductors, metal oxides, and organic/inorganic materials, is explored. Finally, the outlook for betavoltaic battery is discussed before concluding the review.