Micronuclear battery based on a coalescent energy transducer.

Abstract

Micronuclear batteries harness energy from the radioactive decay of radioisotopes to generate electricity on a small scale, typically in the nanowatt or microwatt range^1,2. Contrary to chemical batteries, the longevity of a micronuclear battery is tied to the half-life of the used radioisotope, enabling operational lifetimes that can span several decades³. Furthermore, the radioactive decay remains unaffected by environmental factors such as temperature, pressure and magnetic fields, making the micronuclear battery an enduring and reliable power source in scenarios in which conventional batteries prove impractical or challenging to replace⁴. Common radioisotopes of americium (²⁴¹Am and ²⁴³Am) are α-decay emitters with half-lives longer than hundreds of years. Severe self-adsorption in traditional architectures of micronuclear batteries impedes high-efficiency α-decay energy conversion, making the development of α-radioisotope micronuclear batteries challenging^5,6. Here we propose a micronuclear battery architecture that includes a coalescent energy transducer by incorporating ²⁴³Am into a luminescent lanthanide coordination polymer. This couples radioisotopes with energy transducers at the molecular level, resulting in an 8,000-fold enhancement in energy conversion efficiency from α decay energy to sustained autoluminescence compared with that of conventional architectures. When implemented in conjunction with a photovoltaic cell that translates autoluminescence into electricity, a new type of radiophotovoltaic micronuclear battery with a total power conversion efficiency of 0.889% and a power per activity of 139 microwatts per curie (μW Ci^-1) is obtained.