What Is an Atomic Battery?

Atomic batteries are radioisotope batteries, also called nuclear batteries. The radioisotopes used are mainly strontium-90 (half-life 28 years), thorium-238 (half-life 89.6 years), and thorium-210 (half-life 138.4 days). The general power is several watts to several kilowatts and the life span is several years to decades . At present, atomic batteries are most commonly used with strontium-90 and thorium-238.

Atomic batteries are radioisotope batteries, also called nuclear batteries. The radioisotopes used are mainly strontium-90 (half-life 28 years), thorium-238 (half-life 89.6 years), and thorium-210 (half-life 138.4 days). The general power is several watts to several kilowatts and the life span is several years to decades . At present, atomic batteries are most commonly used with strontium-90 and thorium-238.

Chinese name

Atomic battery

Principle

Nuclear radioactive energy is directly converted into electrical energy

Radioactive material

238, 147, strontium 90

Features

Long life and light weight

Also known as

Nuclear battery

Atomic battery is nuclear battery, which is a device that directly converts the radiant energy of atomic nuclei into electrical energy.

Some atomic batteries use the radiation emitted by radioactive isotopes to generate heat, which is converted into electrical energy through thermocouples according to the phenomenon of thermoelectricity. Others use the principle that rays act on certain substances to emit light. First, radiation is converted into fluorescence, and then Fluorescence acts on silicon photovoltaic cells to generate electricity. The structure of this atomic battery is basically the same as that of solar cells, and it is a more commonly used atomic battery.

Another type of atomic battery is composed of a radiation source that radiates beta rays (high-speed electron flow), a current collector that collects these electrons, and an insulator between the electron radiation source and the current collector. One end of the radiation source becomes the positive electrode due to the loss of electrons, and one end of the current collector becomes the negative electrode, so a potential difference is formed between the two electrodes. This kind of atomic battery can generate higher voltage, but less current.

Radioactive materials commonly used in atomic batteries include plutonium 238, plutonium 147, strontium 90, and the like. The outstanding characteristics of this battery are: long life, light weight, not affected by the external environment, and reliable operation. Mainly used in artificial satellites, spacecraft, marine beacons and swimming weather buoys, and unmanned lighthouses. Atomic batteries have also been used as a power source for artificial cardiac pacemakers and have been used in medical applications.

Since the United States first developed the plutonium-210 atomic battery (electric power 0.0018 watts) in 1954, various atomic batteries have been developed. Atomic batteries work in two ways: one is to convert the thermal energy generated by radioactive isotope decay into electrical energy, which is a thermal conversion battery; the other is to convert the kinetic energy of radioactive isotope decay particles or its secondary effects into electrical energy. Is the dynamic transduction type. At present, research is the most mature, and static thermoelectric batteries, also known as temperature difference type atomic batteries, have been used in practice. It generates electricity by generating a potential difference using temperature changes. The thermocouple conversion device has a simple structure, small size, light weight, and stable performance, but low conversion efficiency, only 5% to 10%. This battery has a relatively small power, only a few watts to several hundred watts.

Atomic batteries do not require sunlight and electromagnetic interference. They can work in harsh environments such as weightlessness, severe storms, and extremely low temperatures. They have a long service life, so they can be used as auxiliary sources for satellites and space detectors. The "Apollo" lunar test station, the "Yuyun" meteorological satellite, the "Herald" Jupiter probe, and the "Viking" Mars lander are all equipped with a thorium-238 isotope battery.

According to statistics in 2002, the United States installed 40 thorium-238 isotope batteries on 22 spacecraft, including 8 artificial satellites, 5 lunar spacecraft, and 9 detectors. Isotopic batteries are light in weight, long in life, and safe and reliable. The daytime temperature on the moon is as high as 102 ° C, and the temperature drops to -150 ° C at night. The daytime and nighttime high temperature and severe cold alternate, and the change range is very large and the conditions are very harsh. Moreover, the night on the moon is 14 times longer than the night on the earth. In the US "Apollo" moon landing plan, five units of plutonium-238 isotope batteries were set on the moon to power 25 instruments and keep them working normally for a long time.

Atomic batteries, driven by the aerospace industry, have made great progress, mainly in the following aspects: first, the power has been greatly improved, and atomic batteries with nearly kilowatt power have now appeared; second, the improvement of hotspot conversion efficiency. One of the main contents of the "Prometheus" plan approved by the Bush administration in 2003 and costing nearly US $ 1 billion was to develop a new high-efficiency isotope power system ^[1] .