Tiny nuclear battery could power devices for decades

Researchers at Korea's Daegu Gyeongbuk Institute of Science & Technology have 关键字1created a nuclear battery that could turn radiation directly into electricity for decades – but without all the scary stuff associated with nuclear radiation.

Called a dye-sensitized betavoltaic cell, this battery uses beta particles, which are just high-energy electrons. The magic in this battery is the material carbon-14, a radioactive isotope that emits beta particles. These particles strike a titanium dioxide semiconductor coated with a ruthenium-based dye, which knocks electrons loose in the dye, generating an electrical current.

The half-life for carbon-14 decay is about 5,730 years, meaning the battery could theoretically still be producing 50% of its original output after nearly six millennia. However, in the real world, the practical power output would likely degrade much sooner due to materials breaking down over such a timeframe.

The prototype battery has a power density of 20.75 nanowatts per square centimeter per millicurie at 2.86% efficiency. In layman's terms, that's not a lot. Roughly the size of an aspirin or so, it pumps out about 0.4% of the power needed to run a basic pocket calculator. You'd need around 240 more of these little nuclear batteries to start your times tables refresher course.

That being said, it generates enough power to run medical devices like a pacemaker pulse circuit or remote environmental sensors for data logging. It could also power RFID tags or microchips, or trickle charge capacitors for things that need a bigger burst of quick energy. There are a whole host of ultra-low-power consuming tech that this type of battery would suit – and it's still in early development.

Despite what one might normally think of nuclear radiation, the researchers say this design is actually quite safe. The beta particles emitted from carbon-14 are already present in nearly everything, including naturally in the human body. Shielding for such a battery is as easy as a thin piece of aluminum foil. Solid state and made without flammable materials, the little nuclear batteries might be safer than lithium-ion batteries, which are prone to thermal runaway, venting, and explosion.