Radio-photovoltaic cells (RPVCs) are able to offer high reliability and extended operational lifetimes, making them ideal for harsh-environment applications. However, the two-stage energy conversion process inherently limits energy conversion efficiency (ECE). This study presents a novel RPVC design based on a waveguide light concentration (WLC) scheme, employing multilayer-stacked GAGG:Ce scintillation waveguides alternately loaded with ⁹⁰Sr radioisotope sources. Electron beam irradiation tests revealed highly efficient radioluminescence (RL) emission from the edge surfaces of GAGG:Ce waveguide at electron energies exceeding 60 keV. A RPVC prototype incorporating 1.43 Ci of ⁹⁰Sr achieved a maximum output power (P _max) of 48.9 μW, with an unprecedented ECE of 2.96%—the highest reported value for radioisotope-powered RPVCs to date. Furthermore, a multi-module integrated RPVC prototype demonstrated a P _max of 3.17 mW, with a short circuit current of 2.23 mA and an open circuit voltage of 2.14 V. Remarkably, the device exhibited only 13.8% RL performance degradation after a 50-year equivalent electron beam irradiation (total fluence: 5.625 × 10¹⁸ e/cm²), confirming exceptional radiation hardness. These findings demonstrate that the WLC-based RPVCs achieve both high power output and exceptional long-term stability, representing a substantial advancement for facilitating nuclear battery applications.

The growing demand for reliable micropower sources in extreme environments has accelerated the development of betavoltaic cells (BV cells) with high energy conversion efficiency and superior radiation resistance. This study demonstrates an advanced BV cell architecture utilizing three-dimensional TiO₂ nanorod arrays (TNRAs) integrated with a NiO_x hole transport layer (HTL). Monte Carlo simulations were employed to optimize the cell design and determine the fabrication parameters for growing TNRAs on FTO substrates via hydrothermal synthesis. The performance evaluation employed both electron beam (2.36 × 10⁹ e/cm²·s) and ⁶³Ni (3.4 mCi/cm²) irradiation methods. The simulation results revealed optimal energy deposition characteristics, with ~96% of β-particle energy effectively absorbed within the 2 μm thick FTO/TNRA/NiO_x/Au structure. The NiO_x-incorporated device achieved an energy conversion efficiency of 4.84%, with a short-circuit current of 119.9 nA, an open-circuit voltage of 324.2 mV, and a maximum power output of 24.0 nW, representing a 3.76-fold enhancement over HTL-free devices. Radioactive source testing confirmed stable power generation and linear efficiency scaling, validating electron beam irradiation as an effective accelerated testing methodology for BV cell research.

To address the issue of low power output of betavoltaic cells in practical applications, a 63Ni-powered betavoltaic rechargeable Zn-ion battery (BRZiB) is presented in this paper for simultaneously harvesting, converting, and storing beta-radioactive energy within one device. Experimentally, a patterned ZnO microrod array nanostructure was prepared using hydrothermal and lithography methods, in which a 63Ni beta source was deposited by chemical plating to form a 63Ni@ZnO structure for betavoltaic power generation. A carbon-coated VO2 nanocomposite (C@VO2), used as the intercalation host for Zn ions, was coated on the betavoltaic structure for fabricating the hybrid cathode of BRZiB. Without using any external power source, the 63Ni-powered BRZiB demonstrated a voltage rise of 0.3 V in 82 h, which was calculated to have an energy conversion efficiency of 5.1% and an energy density of 128 mWh/g over a half-life of 63Ni (∼100 years). The experimental results verify the effectiveness of multi-energy synergistic conversion in the electrochemical betavoltaic system.

Nanotechnology has emerged as a key driver in radioisotope batteries, which offer unique advantages for long-term, maintenance-free energy supply in deep space exploration, medical implants, and nuclear waste utilization. This review summarizes recent progress in applying nanomaterials and nanostructures to overcome the limitations of nuclear batteries, including low energy conversion efficiency and poor stability. The main content focuses on the three primary conversion mechanisms of thermoelectric, radio-voltaic, and radio-photovoltaic batteries, discussing high-performance thermoelectric nanomaterials such as SiGe alloys, wide-bandgap semiconductors including diamond and SiC for enhanced carrier collection, and nanoscale radionuclide ources to mitigate self-absorption losses. This review further elaborates on how nanostructure regulation and interface engineering have significantly improved carrier collection efficiency and device stability. These advances have enabled notable civilian applications, such as the BV100 and “Zhulong No.1” nuclear batteries. Despite this progress, challenges remain in ensuring long-term material stability under extreme environments, maintaining performance consistency during macroscopic device integration, and addressing the high fabrication costs. The review concludes by outlining future research directions, including the development of novel nanomaterial systems, innovative nanostructure designs, scalable manufacturing processes, and enhanced device stability and safety, to further advance next-generation radioisotope batteries.