Research by a team led by Jae W Kwon at the University of Missouri in the USA has opened the door for the development of a new generation of water-based batteries powered by beta radiation. The technology could potentially be deployed in applications ranging from car batteries to spacecraft.
Betavoltaics – battery technology generating power from radiation – has been studied since the 1950s and the technology was used to power the earliest cardiac pacemakers. Although offering the possibility of long-lived portable power sources, drawbacks have included the small portion of the radiation energy that could be effectively converted into electrical charge, and also damage to the lattice structure of the semi-conductors used in such batteries from the kinetic energy of the beta particles themselves.
Previous work has focused on solid-state materials, but liquids are already known to be effective shielding materials for beta radiation. Kwon's team has demonstrated that liquids can provide an excellent medium for the effective direct conversion of electricity from radioisotopes. Furthermore, the free radicals continuously generated in the liquid by the beta radiation can also generate electricity.
Kwon's team developed a battery using a strontium-90 beta source, with a platinum coated titanium dioxide electrode to collect and convert energy into electrons. The cell contains a water-based semiconducting material, which provides shielding from the radioactive source and absorbs the kinetic energy of the beta particles. When the liquid absorbs radiation energy, radiolysis takes place and free radicals - highly reactive but short-lived chemical species - are produced. These can also be converted into electricity, boosting the cell's power output still further.
The research team says its finding reveals new mechanisms for power generation in radiolytic chemical cells, and paves the way for producing chemical cells with higher power density.
The work has been published in the journal Nature.
Researched and written
by World Nuclear News