Scientists from the British Atomic Energy Authority (UKAEA) and the University of Bristol have created a diamond battery that can operate for more than 5,000 years. The battery, made of carbon-14, has the potential to power devices that are difficult to maintain. These batteries are known as betavoltaic batteries, meaning they convert the waning power of the carbon-14 isotope into electricity. According to a press video shared in 2016 by the University of Bristol, this allows the batteries to continuously generate an electric current.
Carbon-14 is a well-known isotope, used in radiocarbon dating to help determine the age of organic materials. However, once transformed into diamond and then placed inside another layer of diamond, scientists say the isotope becomes a long-lasting battery that can be used in the harshest environments. This means they could be used both in space and on Earth, in places where normal lithium batteries might not operate safely, such as in nuclear-powered spacecraft.
Transform waste into energy
The operation of betavoltaic batteries consists of transforming the decreasing power of radioactive isotopes into electric current. This is possible because isotopes emit beta particles as they decay. These particles then collide with the semiconductor material placed in the battery – the diamond layer in this battery design – and release some electrons. The released electrons are then responsible for creating the electric current in the diamond batteries.
Nuclear waste can last a long time, making long-term storage expensive. And while we’ve found ways to speed up nuclear decay, finding new uses for waste is a great way to help reduce storage costs and promote new developments. In this particular case, the University of Bristol and UKAEA heated used graphite blocks from British nuclear facilities. This allowed scientists to collect carbon-14 from the surface of the blocks in gaseous form and remove it entirely. Not only did this help reduce the radioactivity of the blocks, but it also allowed the researchers and engineers behind these advances to then process the carbon-14 and convert it into diamonds.
However, diamonds remain radioactive because they are made entirely of carbon-14. This means that they must then be placed inside another layer of diamond to help absorb and contain the radiation. In addition to acting as a containment system, the outer diamond layer also helps increase the efficiency of electrical current generation to almost 100%.
A perfectly safe solution that can survive civilization
“Carbon-14 was chosen as the source material because it emits short-range radiation, which is rapidly absorbed by any solid material,” noted Dr. Neil Fox of the School of Chemistry in a press release. Normally, this would mean that carbon-14 is dangerous to ingest or even touch. However, none of this short-range radiation can escape when carbon-14 is placed in a diamond. This means that the amount of radiation detected outside the battery is less than that emitted by a single banana, making these batteries exceptionally safe to use in a variety of ways.
Since carbon-14 has a half-life of 5,730 years, batteries can power whatever is inside them without ever needing to be recharged. This, combined with their lower power output than normal batteries, could make them a perfect alternative for powering devices that don’t need a ton of energy, but are difficult to replace or recharge without surgery or extensive maintenance.
