It has been more than 15 years since American scientists first put forward the concept of miniature nuclear battery in 1999, and this concept is not new. There is no doubt about its feasibility in principle (the transformation of nuclear energy into electric energy conforms to the basic law of energy conservation and is essentially different from the impossibility of perpetual motion machine). It is also the conversion of nuclear energy into electric energy. Why can nuclear power plants play an increasingly important role in people's daily lives, while nuclear batteries seem to stagnate? I think there are several main reasons.

1. size limit; The application place of nuclear battery determines that its size cannot be too large. Although the current nuclear battery mainly wants to use the nuclear decay of radioactive isotopes, compared with nuclear fission used in nuclear power plants or submarines, the energy released by nuclear energy is very small, but the energy released by nuclear energy is released in a limited space and the heat cannot be converted or exported in time, which is likely to lead to battery rupture or explosion with the accumulation of time;

2. Selection of radioisotopes; Although many radioisotopes have been proved or manufactured in nature at present, scientists have not found a satisfactory choice based on radiation type, radiation safety, energy stability, half-life and price (refer to Edison's process of finding suitable filament materials);

3. Safety factors; Due to the public's subconscious fear of nuclear energy, the civil progress of nuclear energy has been very slow. Therefore, even if the research and development of nuclear battery is realized in the laboratory, the evaluation of its safety is still very long, which will inevitably have a great impact on the process of nuclear energy industrialization.