https://www.world-nuclear-news.org/Articles/Nuclear-battery-Chinese-firm-aiming-for-mass-mark Background in wikipedia All good and dandy. But a cursory research on nickel-63, leads to a 2018 Russian paper: In the MIPT page: https://web.archive.org/web/20201027160223/https://mipt.ru/english/news/prototype_nuclear_battery_packs_10_times_more_power A more approachable article for non experts on the matter: https://newatlas.com/nickel-nuclear-battery-design/54884 Loo