A review of radioisotope batteries

Abstract

As an important kind of energy source, radioisotope batteries are attracting more and more academic researchers and people from industry due to the high power density, long lifetime (equal to half life of the radioisotope source), outstanding reliability, without maintenance, miniaturization and wide application compared with traditional dry batteries, chemical batteries, fuel batteries and solar batteries. Based on the optimization of functional materials and energy conversion types, radioisotope batteries have been developed for more than 15 species since the first β battery invented by Henry Mosley in 1913. This review describes historical background and development, limitations of key techniques in radioisotope batteries. The radioisotope source loading methods and thermocouple materials of radioisotope thermoelectric generator (RTG), the semiconductor materials and energy conversion units of radiation voltaic isotope batteries (RVIB) are analysed in detail. After an introduction of the basic principles and design requirements of radioisotope batteries, we discuss the technical proposals of different energy conversions for radioisotope batteries. Then, the most recent experimental results for several configurations and experimental set-ups of radioisotope batteries are introduced detailedly, including static thermoelectric type radioisotope batteries, radiation voltaic effect radioisotope batteries, dynamic energy transformation radioisotope batteries and piezoelectric energy transformation radioisotope batteries. The figure for PCEs (Power Conversion Efficiencies) in different radioisotope batteries from 1913 to 2015 is first demonstrated in the end, which illustrates the PCEs of RTG, RVIB are close to 10% and DIPS (Dynamic Isotope Power System) is higher than 23%. Thus, the PCEs of radioisotope batteries will increase effectively if some various high efficient energy conversion types like RTG, RTPV (Radioisotope thermophotovoltaic) and RTIGs (Radioisotope Thermionic emission Generators) are assembled. In the future, four main trends for radioisotope batteries include the better safety and reliability, the higher output power and power matching, the micro/nano integration and module combination of battery structure, the production of radioisotope source. We believe that the research and application of radioisotope batteries will be much attractive with the break through of these aspects made by academic and industrial world.