A team of physicists and engineers affiliated with several institutions in China has developed an extremely small nuclear battery that they claim is up to 8,000 times more efficient than its predecessors. Their paper is published in the journal Nature.
Scientists have been looking for a way to create tiny nuclear power packs for decades. These could power virtually any device, from phones to robots and cars, for many years. Unfortunately, the development of such power packs has been stymied by the dangerous nature of nuclear power plants, regardless of size.
One approach is the development of devices powered by batteries that are charged by nuclear material. Such devices have tended to be small to reduce the amount of nuclear material needed, which has reduced the potential amount of power they could produce. They are also extremely inefficient.
In this new study, the research team found a way to create such a device that is far more efficient.
The device designed and built by the researchers is relatively simple and straightforward. They placed a small amount of americium into a crystal and then used its radiated energy (alpha particles) to produce light. The result is a crystal that glows green.
They connected the crystal to a photovoltaic cell that converts the light to electricity. The device was then placed inside a quartz cell to prevent radiation leakage.
In testing their device, the team found that it could remain charged for a long time -- perhaps as long as decades. They note that the half life of americium is 7,380 years, but the radiation would erode the materials housing it long before that.
Further testing showed the device to be approximately 8,000 times more efficient than any other nuclear-powered battery system developed to date, though they note that the amount of power produced is very small -- it would take 40 billion of these power packs to light a 60-watt bulb.
The researchers suggest further refinement could lead to tiny power packs for small, remote devices such as those sent into deep space.