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.

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.

In Robert Heinlein's Friday, Shipstones are made in factories and come in various sizes, some large enough to power ocean freighters and even spaceships. Others are smaller, intended to power a home or even a small tool, like a drill.

...the place was dark as ink...

So whip out your pocket torch, Friday, powered with its own tiny lifetime Shipstone, and search.