The battery uses the radioactive isotope carbon-14 – known for its role in carbon dating – to generate small amounts of electricity through radioactive decay. With a half-life of 5,700 years, the isotope could potentially power low-wattage devices almost indefinitely.
The specific energy density (J/kg) of radioisotopes is intrinsically higher than chemical energy sources by many orders of magnitude, due to the energetics of nuclear decay, but the appropriateness of a radioisotope source for a given battery power application also depends on the specific power density (W/kg).
The Nano Diamond Battery, developed by a California-based NDB company, utilizes radioactive wastes (C-14) to generate electricity encapsulated in an artificial diamond case. The company claims that this battery can deliver electricity for thousands of years.
With a half-life of 5,700 years, the isotope could potentially power low-wattage devices almost indefinitely. Possible applications include biocompatible batteries for medical devices like ocular implants and pacemakers, eliminating the need for surgical intervention when batteries reach end-of-life.
Radioisotopes utilized in beta-voltaic batteries (e.g., Ni-63, Pm-147) are produced by the DOE Isotope Program. In traditional beta-voltaic batteries, the radioisotope is deposited onto a metal foil that is placed on top of a semiconductor converter. The interaction between the radioisotope and the converter can limit RPS performance.
The interaction between the radioisotope and the converter can limit RPS performance. This research demonstrated an approach where long-lived beta-emitting radioisotopes can be used to match the power density (the ability to release power) of chemical batteries while surpassing them in energy density (the ability to store power).