‘Diamond-age’ of power generation as nuclear batteries developed
New technology has been developed that uses nuclear waste to generate electricity in a nuclear-powered battery.
The short lifespan of conventional batteries means they either cannot be used or have significant drawbacks in situations where it is not feasible to charge or replace them. For example, pacemakers, satellites, high-altitude drones or even spacecraft are low-power electrical devices where long life of the energy source is needed.
What we’re doing
A team of physicists and chemists from the University of Bristol have grown a man-made diamond that, when placed in a radioactive field, is able to generate a small electrical current.
This innovative method for radioactive energy was presented at the Cabot Institute’s sold-out annual lecture - ‘Ideas to change the world’- on Friday, 25 November 2017.
Unlike the majority of electricity-generation technologies, which use energy to move a magnet through a coil of wire to generate a current, the man-made diamond is able to produce a charge simply by being placed in close proximity to a radioactive source.
Tom Scott, Professor in Materials in the University’s Interface Analysis Centre and a member of the Cabot Institute, said: “There are no moving parts involved, no emissions generated and no maintenance required, just direct electricity generation. By encapsulating radioactive material inside diamonds, we turn a long-term problem of nuclear waste into a nuclear-powered battery and a long-term supply of clean energy.”
The team have demonstrated a prototype ‘diamond battery’ using Nickel-63 as the radiation source. However, they are now working to significantly improve efficiency by utilising carbon-14, a radioactive version of carbon, which is generated in graphite blocks used to moderate the reaction in nuclear power plants. Research by academics at Bristol has shown that the radioactive carbon-14 is concentrated at the surface of these blocks, making it possible to process it to remove the majority of the radioactive material. The extracted carbon-14 is then incorporated into a diamond to produce a nuclear-powered battery.
How it helps
The UK currently holds almost 95,000 tonnes of graphite blocks and by extracting carbon-14 from them, their radioactivity decreases, reducing the cost and challenge of safely storing this nuclear waste.
Dr Neil Fox from the School of Chemistry explained: “Carbon-14 was chosen as a source material because it emits a short-range radiation, which is quickly absorbed by any solid material. This would make it dangerous to ingest or touch with your naked skin, but safely held within diamond, no short-range radiation can escape. In fact, diamond is the hardest substance known to man, there is literally nothing we could use that could offer more protection.”
Despite their low-power, relative to current battery technologies, the life-time of these diamond batteries could revolutionise the powering of devices over long timescales. The actual amount of carbon-14 in each battery has yet to be decided but one battery, containing 1g of carbon-14, would deliver 15 Joules per day. This is less than an AA battery. Standard alkaline AA batteries are designed for short timeframe discharge: one battery weighing about 20g has an energy storage rating of 700J/g. If operated continuously, this would run out in 24 hours. Using carbon-14 the battery would take 5,730 years to reach 50 per cent power, which is about as long as human civilization has existed.
The development could solve some of the problems of nuclear waste, clean electricity generation and battery life.
“There are so many possible uses that we’re asking the public to come up with suggestions of how they would utilise this technology by using #diamondbattery.”
Lead researcher profile
Professor Tom Scott, Professor in Materials
Related research centres
Due to the high level of interest this technology has attracted, we've prepared an FAQ which you can download here: Diamond Battery FAQs (PDF, 350kB).