The Preparation and Modification of Strontium Titanate Ceramic Films for High-Performance Flexible Supercapacitor

Abstract

Based on previous research, the perovskite-type SrTiO3 can be considered as a potential energy storage material because of its good electrical conductivity properties and oxygen-vacancy structure. In this work, Ce-doped SrTiO3 nanofibers film with excellent flexibility was successfully fabricated by using electrospinning and conventional sintering route at 600 °C. For the series of the SrCexTi1-xO3 (SCTO-x) films (0≤x≤0.5), although the corresponding nanofibers structure could remain intact, their lattice structure transferred from cubic into tetragonal phase with the increase of Ce doing amount. Moreover, the electrochemical measurement results shown that the working electrode fabricated by SCTO-0.3 sample as active materials exhibited the best electrochemical performance possessing with a maximum specific capacitance value of 2895 mF ⋅ cm−2 at 3 mA ⋅ cm−2 (1809.4F ⋅ g−1 at 1.875 A ⋅ g−1).Therefore, a symmetrical flexible device was assembled by two SCTO-0.3 electrodes with 1 M Na2SO4 solution, showing a good energy density of 89.5 Wh ⋅ kg−1 (at power density of 1250 W ⋅ kg−1). However, while the super-concentrated electrolyte (1 M Na2SO4+66.7 wt % sucrose) was instead of the 1 M Na2SO4 solution in the fabrication of the device, it could display higher energy density (151 Wh ⋅ kg−1 vs. 1600 W ⋅ kg−1), good cycling stability and better mechanical flexibility. Herein, this work may provide a new potential electrode material for flexible energy storage device design.