A South Korean team has presented a new kind of electric battery.
Presented as a silicon carbide betavoltaic cell, it is designed to provide electricity fully autonomously for more than 50 years. This miniature device targets sensors installed in space, ocean depths, or other hard-to-reach environments.
A betavoltaic cell directly converts electrons emitted by a radioactive isotope into electric current. Its operation resembles that of a solar panel, but light is replaced by beta particles. The output remains low, but it can continue for several decades.
Illustration of the silicon carbide betavoltaic cell
Researchers at the Korea Electrotechnology Research Institute chose nickel-63 as the radioactive source. This isotope has a long half-life and emits low-energy beta particles. They are captured by a silicon carbide diode, a material resistant to heat and radiation.
The prototype produced up to 160 microwatts per square centimeter of active surface area. This power is only enough to run very low-power equipment or gradually charge a small storage device.
Tests indicate that a more uniform radioactive layer could improve performance. The researchers estimate a potential of 0.85 milliwatts per square centimeter in an optimized configuration. Several cells could also be stacked or combined.
This technology will not replace batteries for vehicles or powerful devices. It could mainly power beacons, sensors on standby, or instruments that are inaccessible.