Tiny nuclear battery promises decades of uninterrupted power in sea, space

Researchers have created a nuclear battery with unprecedented efficiency: 8,000 times more efficient. The battery developed by the research team at China’s Soochow University harnesses the energy of radioactive decay, a process associated with nuclear waste.

“Micronuclear batteries harness energy from the radioactive decay of radioisotopes to generate electricity on a small scale, typically in the nanowatt or microwatt range,” said researchers in their study.

They state the process of radioactive decay is not influenced by environmental factors, including temperature, pressure, and magnetic fields.

“It makes the micronuclear battery an enduring and reliable power source in scenarios in which conventional batteries prove impractical or challenging to replace.”

This development brings us closer to a future where miniature power sources can operate for decades without needing a recharge.

Innovative design

Notably, the concept of utilizing radioactive decay to create long-lasting batteries has intrigued scientists for over a hundred years. However, low efficiency has previously limited their practical use.

This innovative battery design is based on the strategic combination of materials. The team utilized americium, a radioactive element usually considered nuclear waste, which emits energy through alpha particles.

These particles are highly energetic but tend to lose their energy quickly to their surroundings, making them difficult to harness efficiently.

“Severe self-adsorption in traditional architectures of micronuclear batteries impedes high-efficiency α-decay energy conversion, making the development of α-radioisotope micronuclear batteries challenging,” noted the study .

Transforming energy

To address this, the researchers embedded americium in a specialized polymer crystal that acts like a transformer. It changes the fleeting energy of alpha particles into a stable and sustained green luminescence.

This glowing crystal is subsequently paired with a photovoltaic cell, which is a device that converts light into electricity. It is similar to a miniature solar panel but powered by the green glow from the americium-doped crystal instead of sunlight.

The setup is then encased in a small quartz cell. The result is a micro-nuclear battery that, despite its minuscule size, can generate a stable supply of electricity for decades.

“Contrary to chemical batteries, the longevity of a micronuclear battery is tied to the half-life of the used radioisotope, enabling operational lifetimes that can span several decades,” remarked the study.

Testing revealed that this battery could produce a steady electricity supply for over 200 hours, demonstrating exceptional longevity. It manages to do so with minimal radioactive material, making it a safer and more sustainable option.

Despite americium’s extensive half-life of 7,380 years, the operational lifespan of the nuclear battery is expected to span only a few decades. This limitation arises because the components encasing the radioactive material will gradually degrade over time due to radiation exposure.

Applications and future potential

This breakthrough has been recognized as significant, with experts like Michael Spencer from Morgan State University in Maryland noting the “much improved conversion efficiencies and output power” compared to earlier versions.

While the power output of this battery is currently modest, requiring billions of them to light a single bulb, the potential is immense.

Meanwhile, the research team is focused on enhancing the battery’s efficiency, power output, safety, and usability, considering the caution required when handling radioactive materials.

“Ideally, we envision our micronuclear battery being used to power miniature sensors in remote or challenging environments where traditional power sources are impractical, like deep-sea exploration, space missions or remote monitoring stations,” concluded Shuao Wang from Soochow University.

Although challenges remain, this development represents a major step toward a future where nuclear batteries could be widely used.