Abstract: Betavoltaic batteries have great application potential in the field of low-power electronic devices, such as micro-electro-mechanical-systems(MEMS), due to their long service life, high power density, small scale, strong environmental adaptability and sustainable power supply. At present, the structure design of this type of isotope battery is unsatisfactory, the carrier recombination is serious and the output performance is low. In view of the existing deficiencies, this paper introduced the research progress on the optimization design of betavoltaic batteries in the Isotope Battery Research Group of Jilin University. By using the Monte Carlo code and the finite element analysis software, a simulation model which can accurately predict the output performance of this type of isotope battery was established, and the transport and collection characteristics of radiation-induced carriers were investigated. GaAs was selected as the energy conversion semiconductor material for the experimental preparation of isotope batteries, and the hole/electron transport layers were introduced to the GaAs-based energy converter to enhance the transport and collection of radiation-induced carriers. Moreover, the established simulation model was used to predict the output performance of betavoltaic batteries based on wide-bandgap semiconductor materials. The effect factors on battery conversion efficiency were analyzed, and the relationship between battery conversion efficiency and semiconductor material bandgap was clarified. In addition, a core-shell nanowire betavoltaic battery was proposed to improve the absorption rate of beta particles and reduce the surface recombination rate of radiation-induced carriers. Finally, in order to further improve the output performance of betavoltaic batteries, the ideal of energy carrying-energy converting integration was proposed.