Please don your skeptic hats before reading this article. I'm mainly fascinated that companies with such extraordinary claims can survive or even get enough backing to exist.
"Micro-batteries Nuclear engineers at the University of Wisconsin, Madison have explored the possibilities of producing minuscule batteries which exploit radioactive nuclei of substances such as polonium or curium to produce electric energy. As an example of an integrated, self-powered application, the researchers have created an oscillating cantilever beam that is capable of consistent, periodic oscillations over very long time periods without the need for refueling. Ongoing work demonstrate that this cantilever is capable of radio frequency transmission, allowing MEMS devices to communicate with one another wirelessly.
These micro-batteries are very light and deliver enough energy to function as power supply for use in MEMS devices and further for supply for nanodevices.[12]
The radiation energy released is transformed into electric energy, which is restricted to the area of the device that contains the processor and the micro-battery that supplies it with energy."
https://en.wikipedia.org/wiki/Atomic_battery
I am skeptical but there is great potential in this.
https://www.tdk-electronics.tdk.com/download/2427688/6fa9508...
https://ndb.technology/automotive-battery/
:-)
It's a curiously convoluted sentence.