A new battery designed by researchers in Russia produces power from the beta decay of the radioisotope nickel-63. The nuclear battery delivers about 3,300 mWh of power per gram, which is 10 times more than conventional electrochemical batteries.

The researchers developed a betavoltaic battery using nickel-63 as the source of radiation and Schottky barrier-based diamond diodes for energy conversion. The prototype demonstrated an output power of about 1 microwatt and power density per cubic centimeter of 10 microwatts, sufficient to power a modern artificial pacemaker.

Nickel-63 and stable nickel foil layers were distributed among 200 diamond converters to build the prototype. Prototype nuclear battery. Source: Technological Institute for Superhard and Novel Carbon MaterialsThe amount of power generated is governed by the thickness of the nickel foil and the converter itself, as both affect how many beta particles are absorbed. Power density is maximized by inclusion of two microns-thick nickel-63 sandwiched between diamond diodes measuring 10 microns thick.

New procedures involving ion implantation, chemical vapor deposition and electrochemical etching were developed to synthesize thin diamond plates on a diamond substrate and split them off to mass-produce ultrathin converters. The converters were linked in parallel in a stack and the battery sealed with epoxy.

The open-circuit voltage and the short-circuit current are 1.02 volts and 1.27 microamperes, respectively, and a maximum output power of 0.93 microwatts is obtained at 0.92 V.

In addition to powering pacemakers, the nuclear battery might also find application in space missions.

Researchers from the Moscow Institute of Physics and Technology, the Technological Institute for Superhard and Novel Carbon Materials and the National University of Science and Technology MISIS participated in this development.