Developing Nuclear Batteries as a Recharge-Free Power Solution

Su-Il In, a Professor at Daegu Gyeongbuk Institute of Science & Technology, is developing safe, compact, and durable nuclear batteries. These batteries aim to address the limitations of rechargeable lithium-ion batteries, providing energy sources that can function for decades without the need for recharging. He will present his findings at the American Chemical Society (ACS) Spring 2025 meeting.

Cell phones sometimes lose power earlier than expected, and electric vehicles may run out of charge before reaching their destination. The rechargeable lithium-ion (Li-ion) batteries in these devices typically last for hours or days between charges, but they degrade over time, requiring more frequent recharging.

Researchers are now investigating the potential of radiocarbon as a safe, compact, and cost-effective energy source for nuclear batteries that could operate for decades or longer without needing to be recharged.

The frequent charging demands of Li-ion batteries pose more than just an inconvenience—they limit the effectiveness of technologies that rely on them, such as drones and remote-sensing equipment.

Additionally, the environmental impact of Li-ion batteries is significant, as lithium mining is energy-intensive, and improper disposal can harm ecosystems. With the increasing use of connected devices, data centers, and computing technologies, the demand for longer-lasting batteries continues to grow.

However, simply improving Li-ion batteries may not be the solution to this challenge. “The performance of Li-ion batteries is almost saturated,” says In. As a result, In and his team are working on developing nuclear batteries as a more sustainable alternative to lithium-ion technology.

Nuclear batteries generate power by utilizing high-energy particles emitted by radioactive materials. Not all radioactive elements produce harmful radiation; some can be safely contained using specific shielding materials. For example, beta particles (or beta rays) can be blocked with a thin sheet of aluminum, making betavoltaics a promising and potentially safe option for nuclear batteries.

To explore this approach, the researchers developed a prototype betavoltaic battery using carbon-14, a radioactive isotope of carbon known as radiocarbon.

I decided to use a radioactive isotope of carbon because it generates only beta rays.

Su-Il In, Professor, Daegu Gyeongbuk Institute of Science & Technology

The use of radiocarbon, a by-product of nuclear power plants, presents several advantages. It is a cost-effective and readily available material that is easily recyclable. Its slow degradation rate also makes it an ideal candidate for long-lasting energy storage solutions, potentially powering batteries for thousands of years.

In a typical betavoltaic battery, electrons emitted by radioactive decay strike a semiconductor, generating electricity. Semiconductors are critical in these batteries as they convert the energy from the emitted particles into usable power. To enhance efficiency, researchers are exploring advanced semiconductor materials that can improve energy conversion, ensuring better utilization of the emitted electrons for electricity generation.

To significantly improve the energy conversion efficiency of their novel design, the researchers, led by In, used a titanium dioxide-based semiconductor, a material commonly used in solar cells. This material was sensitized with a ruthenium-based dye, and the bond between the titanium dioxide and the dye was further strengthened through treatment with citric acid.

Upon the collision of beta rays from radiocarbon with the treated ruthenium-based dye, a series of electron transfer reactions, referred to as an electron avalanche, was triggered. This avalanche propagated through the dye, and the titanium dioxide effectively collected the generated electrons.

The new battery design also incorporated radiocarbon into both the dye-sensitized anode and cathode. By treating both electrodes with the radioactive isotope, the researchers increased the amount of beta rays generated. They minimized the loss of beta-radiation energy due to the distance between the two structures.

In prototype demonstrations, the researchers observed that beta rays emitted from radiocarbon on both electrodes triggered the ruthenium-based dye on the anode, generating an electron avalanche that was collected by the titanium dioxide layer and passed through an external circuit, resulting in usable electricity. Compared to a previous design where radiocarbon was only present on the cathode, the new battery design with radiocarbon on both the cathode and anode exhibited a significant increase in energy conversion efficiency, rising from 0.48 % to 2.86 %.

These long-lasting nuclear batteries have the potential to enable a wide range of applications, according to In. For example, a pacemaker could potentially last the lifetime of the patient, eliminating the need for surgical replacements.

However, the betavoltaic design only converted a small fraction of radioactive decay into electrical energy, leading to lower performance than conventional Li-ion batteries. In suggests that further optimization of the beta-ray emitter's shape and the development of more efficient beta-ray absorbers could enhance the battery's performance and increase power generation.

This research received financial support from the National Research Foundation of Korea and the Daegu Gyeongbuk Institute of Science & Technology Research & Development Program, which is funded by the Ministry of Science and Information and Communication Technology of Korea.