Scientists and engineers from the UK Atomic Energy Authority (UKAEA) and the University of Bristol have successfully created the world's first carbon-14 battery
“Diamonds are forever” is the title of a famous novel by Ian Fleming from the 007 series, and today the world of research is trying to prove the validity of this statement in the energy field. A group of scientists from the University of Bristol and the UK Atomic Energy Authority (UKAEA) has created the first 14C diamond battery, capable of lasting thousands of years.
What is it? It is a storage device that harnesses the decay of the radioactive isotope carbon-14 to generate low levels of energy. However, it is so safe that it could be used in medical devices such as pacemakers, hearing aids, and even ocular implants. At the same time, it is so durable that it can withstand extreme environments like space.
Before understanding the breakthrough of British research, it’s important to take a step back.
What is a Diamond Battery?
The diamond battery, also known as a “nuclear battery,” is a betavoltaic cell that generates electricity from the kinetic energy of beta particles emitted by a radioactive source. In this specific case, the beta particles come from Carbon-14 (14C) in a diamond-like form.
In more detail, when radiocarbon decays into Nitrogen-14, it emits a beta particle, which is a high-energy, high-speed electron. This electron collides with other carbon atoms, creating a cascade of low-energy electrons that are collected by an external electrode.
The diamond battery represents a long-sought concept that had never been achieved until now. Although betavoltaic cells were invented in the 1970s, the use of Carbon-14 was long prohibited. The breakthrough came with research in 2016 by the University of Bristol, which led to the creation of the first nickel-63 battery.
Today, the work from the university marks a historic milestone with the unveiling of the first prototype using Carbon-14. “This new type of battery has the potential to power devices for thousands of years, making it an incredibly long-lasting energy source,” reads the press release shared by the UK government.
How Much Energy Does the Carbon-14 Battery Generate?
To answer this question, it’s useful to reference the FAQ document published by the University of Bristol some time ago (which could be updated).
The C14 battery generates at least 2V of voltage and, compared to a standard AA alkaline battery, it should provide 15J of energy per day with just 1 gram of the radioisotope. While this is relatively low, it maintains this power output for 5,730 years. The approximate size of the prototype is 10mm x 10mm with a thickness of up to 0.5mm, excluding metallic contacts and wiring.
How Safe Are Diamond Batteries?
According to Sarah Clark, Director of the Tritium Fuel Cycle at UKAEA, “diamond batteries offer a safe and sustainable way to provide continuous microwatt-level power.” The technology “uses synthetic diamond to securely encapsulate small amounts of carbon-14.” Beta particles can be easily stopped by a few millimeters of shielding, and the devices would not emit dangerous radiation. “Our micropower technology can support a wide range of important applications, from space technologies and safety devices to medical implants,” commented Tom Scott, Professor of Materials at the University of Bristol.
This wouldn’t be the first time a betavoltaic device has been used in the medical field. In the 1970s, betavoltaic cells based on promethium were safely used in pacemakers before being replaced by cheaper lithium batteries.
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Of course, the technology was originally developed with a very specific goal in mind, which has little to do with health. The diamond battery serves as a way to recycle waste from nuclear power plants. “By encapsulating radioactive material within diamonds, we turn a long-term nuclear waste problem into a nuclear-powered battery and a long-term source of clean energy,” explained Professor Scott a few years ago.
As emphasized by UKAEA itself, today’s development is partly considered a result of ongoing work on fusion energy.
