This tiny nuclear battery powers devices for decades on single recharge, scientists claim

A small prototype nuclear battery powered by a radioactive form of carbon can safely power devices for decades – and possibly even for a user’s entire lifetime – on a single charge, scientists say.

For instance, a pacemaker with such a battery could last a person’s entire lifetime, eliminating the need for surgical replacements, researchers say.

However, the battery needs further optimisation to have better energy conversion efficiency, scientists noted.

In modern times, cell phones and many other mobile devices use lithium-ion batteries, which typically last between hours to days between charges.

However, these batteries degrade with use and need to be charged more frequently.

Mining for lithium also damages the environment as it is energy-intensive and requires large quantities of water.

So, as an alternative to lithium, researchers are considering the development of safe nuclear batteries that do not need frequent charging.

“The performance of Li-ion batteries is almost saturated,” said study lead researcher Su-Il In from South Korea’s Daegu Gyeongbuk Institute of Science & Technology.

These batteries generate power by harnessing high-energy particles emitted by safe radioactive materials that emit radiation, which can be blocked by certain materials.

For instance, beta rays – or high-speed electrons – can be shielded by a thin sheet of aluminium, making betavoltaics a safe choice for nuclear batteries.

In the new study, presented at a recent meeting of the American Chemical Society, researchers demonstrated a prototype betavoltaic battery powered by carbon-14, an unstable and radioactive form of carbon.

This form of carbon produces only beta rays that can be blocked using a metal sheet and is also “readily available” as a by-product from nuclear power plants, scientists say.

“I decided to use a radioactive isotope of carbon because it generates only beta rays,” Dr In says.

In the battery, electrons strike a titanium dioxide-based semiconductor, leading to a “cascade of electron transfer”.

During demonstrations, researchers found that the beta rays released from the radiocarbon on both electrodes generated an electron cascade that passed through an external circuit and produced usable electricity.

Since the radiocarbon degrades very slowly, the battery could theoretically last for an entire lifetime, they say.

“We can put safe nuclear energy into devices the size of a finger,” Dr In said, adding that the batteries can find particular use in medical devices.