Morphology-controlled porous Bi0.9La0.1FeO3 microspheres for applications in supercapacitors

Morphology-controlled porous Bi0.9La0.1FeO3 (BLFO) microspheres with high specific surface area and pore volume have been synthesized by a novel one-step etching approach, in which BLFO particles were used as precursors, hydrazine and methyl mercaptoacetate function as reducing and complexation agent respectively. As the etching time goes in order from 30 to 90 min, different morphologies of porous BLFO microspheres can be obtained, such as dandelion, corolla, and acanthosphere-like architectures respectively, which corresponds to different surface area and pore volume of porous BLFO microspheres. Particularly, porous BLFO microspheres etched for 60 min has the largest specific surface area of 75.09 m2 g-1 m2g, much larger than 1.44 m2 g-1m2, that of unetched BLFO particles. The enhanced surface area and pore volume brings about a great number of active sites that boost the intercalation and de-intercalation of electrolyte ions, and compared with unetched BLFO particles, porous BLFO microspheres exhibit the good conductivity and ion diffusion behavior, which are both conducive to excellent performance as supercapacitors. The largest specific capacitance of 561.48 F g-1 Fg−1 at a scan rate of 2 mV s-1mV/s can be obtained when the etching time is 60 min, and it exhibits a good capacitance retention of 85.76% after 1500 cycles with the current density of 5 A g-1A/g, much superior to 75.66%, that of BLFO particles. This research may offer a facile method to fabricate stable, flexible and high performance energy storage devices.