Stefan Mileschin

A newly introduced battery called the BV100 by Chinese Betavolt Technology promises to provide half a century of power, at 100 μW in a 15x15x5 mm package. Inside the package are multiple, 2 micron-thick layers nickel-63 isotope placed between 10 micron-thick diamond semiconductor, with each diamond layer using the principle of betavoltaics to induce an electrical current in a similar fashion to a solar panel using light. Ni-63 is a β emitter with a half-life of 100 years, that decays into copper-63 (Cu-63), one of the two stable forms of copper.

https://hackaday.com/2024/01/16/beta...-for-50-years/