The noticeable progression in the power electronic devices pushes a crucial demand to develop dielectrics with low loss, good temperature stability and high energy-storage density in addition to enhanced energy recovery characteristics. These properties are very important in order to use in advanced pulsed capacitors. Capacitors form a main part of many modern electrical and electronic devices. In this regards, relaxor ferroelectrics form an appropriate candidate for ceramic-based capacitor applications, due to their low loss and high energy density. This review provide theoretical basis at first, which help to evaluate the capacitors characteristics that contribute to high energy storage behavior. Moreover, serves to give an overall summary on latest development on electric energy-storage performance in the candidate materials, particularly in bismuth based peroviskite materials. For example, Bi0.5Na0.5TiO3, BiFeO3 and their solid solutions with BaTiO3 or with K0.5Na0.5NbO3.