Korean researchers develop silicon carbide beta battery that runs 50 years without recharging

A research team led by Dr. Seo Jae-hwa at the Korea Electrotechnology Research Institute's (KERI) Next-Generation Semiconductor Research Center has developed a silicon carbide (SiC) semiconductor-based beta battery capable of generating electricity on its own for more than 50 years without recharging or replacement — even in extreme environments such as outer space, polar regions and the deep sea, KERI announced Sunday.

A beta battery is a next-generation power device in which a semiconductor absorbs electrons — known as beta rays — emitted naturally by radioactive material and converts them into electricity. The concept is similar to a solar cell, which generates electricity from light, except that radioactive material serves as the energy source instead of sunlight. This allows the battery to supply power stably over very long periods regardless of weather or temperature, even in environments with no sunlight, such as deep space, the ocean floor or underground defense monitoring installations. Existing technology, however, suffered from low charge-collection efficiency, and a lack of domestic infrastructure capable of safely handling radioactive materials and measuring performance had placed significant constraints on demonstrating the technology in practice.

To overcome these limitations, KERI selected silicon carbide — a next-generation material far more resistant to heat and radiation than conventional silicon semiconductors — as the core component. The team then optimized the semiconductor structure using a p-i-n diode configuration to maximize the efficiency of converting radiation into electricity, successfully producing an original, proprietary device.

With the foundational technology secured, the team turned to what had been the biggest hurdle: demonstrating the battery with actual radioactive material. After clearing stringent safety requirements, the researchers obtained nickel-63 (Ni-63) — the beta-ray source used in the battery — and built South Korea's first dedicated measurement facility for the purpose. Combining the semiconductor with the radioactive material, they achieved a power output of approximately 160 microwatts per square centimeter (μW/cm²) based on the effective active area, enough to illuminate a low-power LED in a working prototype. Taking into account the decay characteristics of Ni-63, the result demonstrates that devices requiring only minimal power could operate for more than 50 years without a battery replacement.

That output figure represents an improvement of more than 60,000 times over previously reported domestic experimental results — the highest level ever recorded in South Korea.

The team also demonstrated that applying a thin, uniform coating of radioactive material across the entire semiconductor surface could yield a power density of 0.85 milliwatts per square centimeter (mW/cm²) and more than 20 microwatts (μW) per unit cell. Given the half-life of the nickel-63 used, the battery could theoretically operate for up to 100 years. Scaling up cell size and stacking cells through an integration process would make the underlying technology competitive with commercially available products from leading overseas companies.

"A beta battery is a power source that can be used for decades in harsh environments such as outer space and the deep sea," Seo said. "It will serve as the core power driver for unmanned defense surveillance sensors that store energy while consuming extremely little power and transmit signals periodically, as well as for emergency beacons in space and the deep sea — enabling them to operate autonomously for more than 50 years."

The team has filed patent applications covering the beta battery manufacturing technology and measurement infrastructure developed through this research. It plans to pursue technology transfers and joint product development in collaboration with companies in the aerospace, defense, nuclear power plant and radiation safety monitoring, and remote sensor sectors.

The findings were published in the International Journal of Energy Research.