Can a thumb-sized nuclear battery last 50 years?

The race to build a nuclear battery is heating up, with a Chinese startup pitching a coin-sized device it says can keep producing a charge for 50 years.

Beijing-based Betavolt is joining a field that includes Australia’s PhosEnergy, which was given $2.3 million in 2022 to explore producing ultra-long-life batteries for the Department of Defence.

Betavolt is aiming for a much larger market with smaller devices powering mobile phones, laptops and drones.

“If policies permit, atomic energy batteries can allow a mobile phone to never be charged, and drones that can only fly for 15 minutes can fly continuously,” Betavolt says in a statement.

Public policy may be a problem. Existing coin-sized lithium-ion batteries can cause life-threatening injuries if swallowed as their charge can burn through a child’s oesophagus within a few hours.

Betavolt says the energy density of its tiny unit is 10 times that of similar-sized lithium batteries. But a small nuclear battery could pose an additional risk: beta radiation.

The proposed battery harnesses beta radiation released from a radioactive nickel isotope and converts this into electricity. Beta particles are not the most dangerous form of radiation. It is a high-speed, high-energy, but low-mass electron.

It cannot travel as far as an X-ray or carry as much energy as an alpha particle. And while it has sufficient impact to pierce several millimetres of skin, small amounts of shielding can provide adequate protection. Like a lithium-ion battery, the most significant health risk will likely be if ingested.

China’s Betavolt believes the potential for a long-life battery for drones, robotics and autonomous systems far outweighs any risk, adding its development puts China “way ahead” of European and American scientific research institutions and enterprises.

It says production has entered the pilot stage, with mass production expected in 2025.

Meanwhile, PhosEnergy is working with the University of Adelaide to exploit the relative safety of beta radiation isotopes as power packs for space-based satellites and rovers.

“In recent proof of concept experiments, GenX’s unique semiconductor-metal electrode configuration has been shown to effectively harvest power from the semiconductor layer when excited,” the company says.

“A demonstration unit is currently under construction with a prototype unit planned to follow, which will be tested in a space equivalent environment to allow commercial demonstration.”

Sign up to our weekly newsletter

Please login to favourite this article.