Researchers at Korea's Daegu Gyeongbuk Institute of Science & Technology have created 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.
This isn't the first time atomic batteries have made the news.
The first radioisotope battery was developed in 1954 by the Atomic Energy Commission in the US. It used strontium-90 as the radioactive source and converted energy from beta particles into electricity, similar to today's betavoltaic cells.
Shortly thereafter, in the 1960s, Radioisotope Thermoelectric Generators (RTG) were being used in space missions, converting energy from alpha-emitting isotopes like plutonium-238 – which is more potent but still relatively safe when properly shielded. The very first space mission being a US Navy satellite called Transit 4A – part of the world's first satellite navigation system and precursor to modern GPS.
More recently, Betavolt announced its 3-volt diamond nuclear battery that uses nickel-63 and a diamond semiconductor using the same beta particle principle that can power a device for 50 years.
Arkenlight is another company that's been developing carbon-14 diamonds to produce atomic battery power for several years. It's worth reading the transcript with Morgan Boardman in a New Atlas interview with Arkenlight if you'd really like a deep dive into the technology.
While this tech isn't entirely new, recent breakthroughs in materials, efficiency, and safety are finally starting to light the path to everyday practical applications – no reactors required.
Source: American Chemical Society
