Californian battery company NDB says its nano-diamond batteries act like tiny generators by using leftover radioactive material from nuclear reactors to create electrical energy. Left untreated, the radioactive graphite component is highly dangerous, hard to store safely, and has a very long half-life.
NDB purifies this graphite and uses it to create carbon-14 diamonds. That layer of diamond is coated in another layer, this time, of carbon-12 diamonds, which acts as a tamper proof protector to contain the radioactive material. These structures are then layered to create a cell capable of producing electricity. NDB says that it could repurpose the structure to fit any kind of standardized battery size, like AA, AAA, and so on.