Source: interestingengineering
By: Georgina Jedikovska
Date: Aug 19, 2025
Researchers in China have developed a novel nuclear battery that can withstand at least half a century of radiation and deliver three times the energy efficiency of conventional designs.
The team set out to improve battery performance in extreme environments, led by Haisheng San, PhD, a professor at Xiamen University, and Xin Li, PhD, a researcher at the China Institute of Atomic Energy.
According to the scientists, conventional power systems, especially those used in extreme conditions such as space or deep-sea infrastructure, struggle with long-term reliability.
“Conventional power sources (e.g., chemical batteries, fuel cells, and photovoltaic cells) fail to meet the stringent operational demands of harsh environments, including long-term durability, maintenance-free operation, and continuous self-sustaining capabilities,” the researchers said.
Their limited energy density, sensitivity to environmental factors, and the need for periodic maintenance make them impractical for missions that require continuous, unattended power over many years.
Now, in a bid to address these challenges, the researchers developed strontium-90 radio-photovoltaic cells (RPVCs) built on a waveguide light concentration (WLC) structure.
Advanced RPVC technology
The innovative design integrates multilayer-stacked GAGG: Ce (Cerium-doped gadolinium aluminum gallium garnet) scintillation waveguides with strontium-90 radioisotopes.
GAGG: Ce is a single-crystal scintillator known for its excellent photon detection capabilities. It is among the brightest available, with an emission peak at 520 nanometers (nm).
The setup converts radioactive energy into light, which is then directed toward photovoltaic cells that generate electricity.
In performance trials, a single RPVC unit achieved an energy conversion efficiency of 2.96 percent, significantly higher than existing RPVC designs.
In addition, the team reported an output of 48.9 microwatts (μW) from a single unit, with a multi-module version reaching 3.17 milliwatts (mW).
The prototype also demonstrated a short-circuit current of 2.23 milliamperes (mA) and an open-circuit voltage of 2.14 volts (V). “We designed and fabricated an RPVC that achieves a balance between efficiency and stability,” the scientists said.
A long-term power solution
Most notably, when the team simulated long-term use by exposing the RPVCs to electron beam irradiation equivalent to 50 years of radiation exposure, the devices showed only a modest 13.8 percent drop in optical performance.
Summarizing the advantages of the discovery, the team elaborated that WLC-based RPVCs can achieve both high power output and outstanding long-term stability, representing a substantial advancement in facilitating nuclear battery applications.
“The WLC structure realizes a 3-fold improvement in energy conversion efficiency compared with conventional RPVC structures,” the researchers explained.
“The irradiation equivalent to 50 years of service confirms that WLC-based RPVCs have great long-term service stability,” they added. The system minimizes energy loss by focusing light from the scintillator directly into the photovoltaic cells while requiring no moving parts or external energy input.
“Although large-scale production of RPVCs is still limited by challenges such as mass production and cost reduction of strontium-90 radioisotopes, the current research results mark a substantial step forward in promoting nuclear battery applications,” the researchers concluded in a press release.
