The design of a direct charge nuclear battery with high energy conversion efficiency

Direct charging nuclear batteries (DCNB) have the potential of being widely used to meet the special requirements in the area of aerospace and ocean. The current application of direct charging nuclear batteries is restricted by the low energy conversion efficiency, commonly less than 10%. This low efficiency is limited mainly by issues of low source efficiency and shunt factor among others, such as collection and geometry factors. Based on a numerical simulation and empirical calculations we here propose a design of DCNB by utilization of a sub-micrometer thickness radiation source to increase the source efficiency, both-side emission, and collection of decay particles to improve the collection and geometry factors, as well as impedance matching of batteries and load to improve the shunt factor, among other various optimizations. The energy conversion efficiency of DCNB with this design reaches over 20%. The successful deployment of the current design should vastly improve the energy conversion efficiency of DCNBs, and also establish a theoretical foundation for extending the scope of applications of DCNBs in the future.