DGIST achieves the world’s highest efficiency with the development of a perovskite-based self-powered betavoltaic battery

□ A research team led by Professor Su-Il In of the Department of Energy Science & Engineering at DGIST (President Kunwoo Lee) successfully achieved a breakthrough improvement in the performance of the radiation absorber, a key component of perovskite-based betavoltaic batteries, by applying additive engineering and antisolvent process control techniques. Through this technology, the team significantly enhanced both the efficiency of converting radiation energy into electricity and long-term stability, thereby succeeding in the development of a high-performance next-generation betavoltaic battery capable of long-term operation without external charging.

□ Recently, with the rapid advancements in artificial intelligence (AI), the Internet of Things (IoT), and space exploration technologies, an increasing demand has emerged for next-generation energy sources capable of supplying stable power over long periods without maintenance, even in extreme environments. However, conventional lithium-ion batteries have limitations, such as limited lifespan, fire risk, and the need for periodic charging and replacement.

□ Receiving attention as an alternative to overcoming these limitations, a betavoltaic battery is a device that converts beta particles (electrons) emitted during the decay of radioactive isotopes into electrical energy. It can generate power autonomously without an external power supply, offers an extremely long lifespan depending on the isotope’s half-life, and allows radiation to be managed at acceptable levels. However, conventional betavoltaic batteries have faced challenges in commercialization due to the low energy conversion efficiency of radiation absorber materials.

□ To address these challenges, the research team led by DGIST Professor Su-Il In applied carbon-14 nanoparticles, a radioactive isotope, as a beta radiation source and introduced perovskite materials as radiation absorbers. In particular, through joint research with Professor Jong Hyeok Park’s research team from the Department of Chemical and Biomolecular Engineering at Yonsei University, the team demonstrated that using methylammonium chloride (MACl) as an additive during the perovskite fabrication process and employing an isopropanol (IPA)-based antisolvent process are effective for crystal growth and defect control.

□ Through this process, the perovskite crystal size was significantly increased and the internal defect density was reduced, thereby creating an environment in which electrons generated by beta-particle collisions can travel without recombination losses. As a result, the team succeeded in inducing the “electron avalanche” phenomenon experimentally, in which approximately 400,000 electrons are generated per incident beta particle.

□ The betavoltaic battery developed by the research team recorded an energy conversion efficiency of 10.79%. This represents an approximately sixfold improvement over the previously reported highest efficiency (approx. 1.83%) for perovskite-based betavoltaic batteries, thus confirming that the device maintained stable power output without performance degradation even during continuous operation tests exceeding 15 hours. This performance is evaluated as surpassing that of comparable international studies reported in Nature in 2024.

□ This study is significant in that it is the first in the world to present a novel design strategy that precisely controls the material and structure of radiation absorbers at the nanoscale, thereby substantially enhancing the efficiency, cost-effectiveness, and commercialization potential of betavoltaic batteries all at the same time. In particular, this study experimentally demonstrates the realization of high-efficiency betavoltaic batteries that had previously remained at the level of theoretical feasibility, and is expected to enable their use as core power sources in fields where battery replacement is difficult, such as implantable medical devices, space exploration equipment, and AI-based autonomous mobility.

□ “This study is significant in that it has overcome the low efficiency limitations of conventional betavoltaic batteries by utilizing perovskite materials and empirically achieved high efficiency exceeding 10%,” stated Professor Su-Il In. “We will continue follow-up research to enable commercialization as an independent power source in Fourth Industrial Revolution industries and future AI technology fields that require energy self-sufficiency.”

□ Meanwhile, this research was supported by DGIST general research programs; the Next-Generation Isotope Battery Core Materials Technology Advancement Project of the Ministry of Science and ICT; the InnoCORE Project of the four major institutes of science and technology; and the Individual Basic Research Program (Mid-career Researcher) of the National Research Foundation of Korea (NRF). The research findings were published online in Carbon Energy (IF 24.2), an international journal in the field of energy and carbon transition.