Nuclear Batteries

Nuclear batteries are special devices that generate electricity by harnessing the heat released during the natural decay of radioactive materials. They typically use plutonium-238 and other isotopes. Their most significant feature is their ability to operate for very long durations (10–50 years) and to provide power even under harsh environmental conditions.

For this reason, they are preferred in spacecraft medical devices and military equipment. Since they have no moving parts, they are silent and, because they require no maintenance, they are reliable.

In light of increasing energy demands today, the need for long-lasting energy sources that operate independently of environmental conditions is growing. In this context, nuclear batteries offer ideal solutions due to their capacity to provide continuous power under harsh environmental conditions. The performance and durability limitations of traditional lithium-ion batteries have directed researchers toward alternative energy generation technologies.

Nuclear batteries operate on the principle of converting the heat energy generated by the decay of radioactive isotopes into electrical energy. There are two main types:

• RTG (Radioisotope Thermoelectric Generator): Generates electricity through the thermoelectric effect.
• Betavoltaic Battery: Generates electricity when beta particles strike semiconductor materials.

Recently, researchers in South Korea have successfully improved the efficiency of betavoltaic batteries by using the carbon-14 isotope. Carbon-14 emits only beta radiation, making it a safer option. Additionally, as a byproduct of nuclear power plants, it is low-cost and recyclable.

Traditional RTGs convert the heat emitted by radioactive isotope decay into electricity using thermoelectric modules. In betavoltaic batteries, beta radiation directly strikes a semiconductor structure, generating an electron flow.

Researchers from the Daegu Gyeongbuk Institute of Science and Technology (DGIST) in South Korea have increased energy conversion efficiency to 2.86 percent by using carbon-14 as both anode and cathode. In this design, beta particles interact with a titanium dioxide-based semiconductor and a ruthenium-based dye to create an “electron avalanche,” which generates electricity.

Space Missions: Used in numerous missions by NASA such as Voyager, Cassini and Curiosity.

Medical Devices: Used in limited applications for devices requiring long-term power, such as cardiac pacemakers.

Defense Industry: Used in long-term monitoring and sensor systems.

Polar Regions and Submarines: Provide power in areas where sunlight is insufficient.

Newly developed carbon-14-based nuclear batteries show potential as long-lasting and reliable power sources in fields such as medical implants, remote sensors and data centers.

• Continuous power generation for 10 to 50 years
• Independence from environmental conditions
• Silent operation and absence of moving parts
• Safer due to carbon-14 emitting only beta radiation

• High production cost
• Safety and environmental risks associated with radioactive materials
• Limited power output (typically a few watts)

With further improvements in efficiency and safety, nuclear batteries could enable new applications ranging from IoT devices and microsatellites to micro-robots. Additionally, researchers aim to enhance efficiency in betavoltaic technologies through the use of nanomaterials. Research in South Korea demonstrates that carbon-14 is a promising candidate for this field.

^{Radyoizotop Termoelektrik Jeneratör (RTG) – Temel Bileşenler (Yapay Zeka Tarafından Oluşturulmuştur)}

• The image above presents a simplified cross-sectional model of the internal structure of a radioisotope thermoelectric generator (RTG).
• The central isotope fuel capsule typically contains a radioactive isotope such as plutonium-238. Its natural decay releases large amounts of heat.
• The surrounding thermoelectric converters directly transform this released heat into electrical energy.
• Radiator fins mounted on the device's outer surface prevent overheating by dissipating excess heat into space or the surrounding environment.

RTGs are preferred in space missions due to their lack of moving parts and reliable performance under harsh environmental conditions.

^{Termoelektrik Dönüşüm Yapısının Detaylı Kesiti (Yapay Zeka Tarafından Oluşturulmuştur)}

• The second image provides a more detailed view of the internal structure of a nuclear battery.
• The central heat source ensures controlled heat production from the isotope. This heat is the most critical element of the system.
• The multilayer insulation layer prevents heat leakage while directing retained heat toward the thermoelectric converters.
• The thermoelectric material used here is a silicon-germanium (SiGe) single couple, known for its high-temperature resistance.
• The aluminum outer casing protects the entire structure and provides mechanical resilience against environmental conditions.

This structure is ideal for long-term power generation in systems with fixed and low power requirements.

^{GPHS-RTG – Gelişmiş RTG Tasarımı (Yapay Zeka Tarafından Oluşturulmuştur)}

• This image shows a full cross-section of the GPHS-RTG (General Purpose Heat Source – Radioisotope Thermoelectric Generator) system.
• Such generators were developed by institutions like NASA for use in space missions.
• The General Purpose Heat Source (GPHS) is located at the center of the system and forms the basis of heat generation.
• This heat is efficiently converted into electricity by thermoelectric modules before being dissipated through multilayer insulation and cooling tubes.
• The silicon-germanium (Si-Ge) single couple is the critical module that directly converts this thermal energy into electrical energy.
• The aluminum outer casing protects the system from external factors.
• The Active Cooling System (ACS) is a specialized manifold that regulates temperature.
• The central heat source support holds the internal modules in place and maintains thermal equilibrium.

Thanks to this complex structure, GPHS-RTGs can be safely used in long-duration and remote environments such as Mars missions.