Relaxor perovskite ferroelectric 0.1Bi(Zn1/2Zr1/2)O-3-0.9BaTiO(3)(0.1BZZ-0.9BT) ceramics were successfully prepared, whose powders synthesized by the sol-gel process, with average grain size about 1.29 mu m. 1.75 J/cm(3) discharge energy density and good dielectric stability were obtained over a wide temperature range from 25 degrees C to 140 degrees C. The pulse discharge capability of 0.1BZZ-0.9BT ceramics was tested under different electric fields. The discharge time was 2.13 mu s, which proved its ability to charge and discharge quickly. Complex impedance analysis and thermally stimulated depolarization current tests were applied to investigate the defect types and activation of 0.1BZZ-0.9BT ceramics. The evolution process of composite defects and oxygen vacancies profoundly affects the dielectric temperature stability of 0.1BZZ-0.9BT ceramics' energy storage property.