Optical nuclear batteries can last for centuries

According to research published in the journal Naturea team of experts seeks to exploit alpha rays released from decaying radioisotopes, in a field where most achievements have focused on beta radiation.

The growing need for clean energy solutions and small, long-lived alternative power sources has sparked interest in nuclear batteries, but radioactive alpha isotopes are seen as the biggest challenger to micro batteries. nuclear. That’s because the high decay energy of alpha radioisotopes, at 4 – 6 mega electron volts (MeV), provides potential far beyond that of devices using beta radioisotopes. Compared to it, the decay energy of the beta isotope is only a few tens of kiloelectron volts at most.

However, alpha particles lose significant energy through the self-absorption effect. This effect sharply reduced the actual capacity of the alpha radioisotope micronuclear battery in tests to a level much lower than predicted in theory, according to lead researcher Wang Shuao of Dongwu University. Wang has spent years focusing on China’s need for sustainable nuclear development.

Together with a research team from the Northwest Institute of Nuclear Technology and Xiangtan University, Wang designed a nuclear battery with an integrated layer that acts like a photovoltaic cell to make optimal use of alpha radiation. The researchers incorporated an energy converter, a layer of polymer surrounding the isotope, which transfers the energy released in radiation by converting it into light, then into electricity, like a photovoltaic cell. Using only 11 microcuries from the 243Am isotope, this combination produces radioluminescence from the alpha rays emitted by the decay process.

Further experiments determined the electrical capacity of the luminescent activity to be 11.88 nanowatts, with an efficiency of converting energy from decay into light reaching 3.43%. The Chinese research team said that their photovoltaic nuclear battery device that converts radioactive activity into electrical energy has an extremely long lifespan and operates regardless of temperature fluctuations. According to the article, the experimental battery has a total electrical conversion efficiency of 0.889% and produces 139 microwatts/curie.

The design has been proven through experiments and test results show that the energy conversion efficiency is 8,000 times higher than conventional battery structures, researchers said. The power converter is extremely stable with virtually unchanged performance parameters over 200 hours of continuous operation. Since the half-life of 243Am lasts several centuries, the battery pack has a similar lifespan.

The above breakthrough not only addresses China’s great need for safe and sustainable nuclear development, but also provides new solutions to utilize nuclear waste.