Runs for 50 Years Without Charging... KERI Achieves Korea's First Beta Battery Demonstration [Reading Science]

KERI Achieves Korea's First Demonstration of "Beta Battery"

Real-World Power Generation Using Nickel-63 and Silicon Carbide Semiconductor

Ultra-Long-Life Power Source Expected for Unmanned Sensors in Space, Deep Sea, and Defense Applications

A beta battery capable of steadily generating a minute amount of power for over 50 years without charging or replacement has been successfully demonstrated in Korea for the first time. There is growing anticipation that this technology could serve as a power source for unmanned sensors deployed in space, deep-sea, and polar regions, where sunlight is scarce or access by humans is challenging.

The Korea Electrotechnology Research Institute (KERI) announced on the 24th that Dr. Jae-Hwa Seo's team at the Next Generation Semiconductor Research Center, in collaboration with Professor Youngjun Yoon's team at Kyungpook National University, has developed a beta battery prototype based on silicon carbide (SiC) semiconductors. The team succeeded in both generating actual electricity and powering a low-power light-emitting diode (LED).

A prototype of a beta battery based on SiC semiconductors, developed and demonstrated for the first time in Korea by KERI. Provided by KERI

A beta battery is a device that converts the electrons, or 'beta rays', emitted during the decay of a radioactive isotope into electricity via a semiconductor. The principle is similar to that of a solar cell, which converts light into electricity; however, instead of sunlight, a radioactive material is used as the energy source.

While the output is much smaller than that of conventional batteries, a key advantage is the ability to supply power for decades without the need for charging or replacement. This makes the technology suitable for powering equipment such as spacecraft, deep-sea instruments, and underground or military unmanned surveillance sensors, where maintenance is extremely difficult.

The research team used silicon carbide, which is more resistant to heat and radiation than conventional silicon, as the semiconductor material. To enhance the efficiency of converting beta rays into electricity, they also applied the 'p-i-n diode' structure, which places a semiconductor layer with minimal impurities between the anode and cathode.

The greatest challenge was performance verification using actual radioactive material. After meeting safety standards, the team procured nickel-63 (Ni-63), which emits beta rays, and established a dedicated facility—unprecedented in Korea—to measure the output of the beta batteries.

The team confirmed that combining the silicon carbide semiconductor and nickel-63 generated electricity, and produced a prototype that could light a low-power LED using the generated power. According to KERI, the measured output was more than 60,000 times higher than any previously reported experimental result in Korea.

From actual device fabrication to space radiation testing

Under optimal conditions, in which the radioactive material is coated thinly and uniformly on the semiconductor surface, the analysis showed that more than 0.85 milliwatts (mW) per square centimeter and over 20 microwatts (µW) per individual cell could be generated. This is more than 4,200 times higher than the previously targeted output per unit cell in Korea.

Nickel-63 has a half-life of approximately 100 years. Considering the lifespan and output degradation characteristics of the radioactive isotope, the research team concluded that the device could operate ultra-low-power equipment for over 50 years, and theoretically, depending on the design, could generate electricity for up to 100 years.

The research team also developed an AI-based output prediction model. This allows the actual output and voltage of the beta battery to be predicted with 98-99% accuracy, significantly reducing the time required to optimize device structure and materials.

To assess durability in the space environment, the team conducted tests in which the beta battery was irradiated with high-energy protons at 15 mega electron volts (MeV). By quantitatively measuring how the battery's performance degraded when exposed to intense cosmic radiation, they obtained reliability data necessary for space mission applications.

Dr. Jae-Hwa Seo of KERI successfully demonstrated the beta battery based on SiC semiconductors for the first time in Korea. Provided by KERI

Dr. Jae-Hwa Seo of KERI stated, "Beta batteries are not devices that deliver large outputs like EV batteries, but they are a power source that can reliably supply small amounts of electricity for decades in remote locations where human access is difficult." He added, "They could be utilized in applications such as military unmanned surveillance sensors or emergency signal devices in space and the deep sea, which collect energy and transmit signals at regular intervals."

Professor Youngjun Yoon of Kyungpook National University explained, "This work is significant because it went beyond computer simulations or basic research, encompassing actual device fabrication, measurement, prototype demonstration, and AI-based design prediction."

The research results have been published in the international scholarly journal for the energy sector, 'International Journal of Energy Research'. The team has completed related patent applications and plans to promote technology transfer and joint product development with companies active in the aerospace, defense, nuclear power/radiation safety monitoring, and remote sensor industries.

This content was produced with the assistance of AI translation services.