Enhancing the Electrochemical Properties of LaCoO₃ by Sr-Doping, rGO-Compounding with Rational Design for Energy...

Perovskite oxides, as a kind of functional materials, have been widely studied in recent years due to its unique physical, chemical, and electrical properties. Here, we successfully prepared perovskite-type LaCoO₃ (LCOs) nanomaterials via an improved sol-gel method followed by calcination, and investigated the influence of calcination temperature and time on the morphology, structure, and electrochemical properties of LaCoO₃ nanomaterials. Then, based on the optimal electrochemical performance of LCO-700-4 electrode sample, the newly synthesized nanocomposites of Sr-doping (LSCO-0.2) and rGO-compounding (rGO@LCO) through rational design exhibited a 1.45-fold and 2.03-fold enhancement in its specific capacitance (specific capacity). The rGO@LCO electrode with better electrochemical performances was further explored by assembling rGO@LCO//rGO asymmetric supercapacitor system (ASS) with aqueous electrolyte. The result showed that the ASS delivers a high energy density of 17.62 W h kg^-1 and an excellent cyclic stability with 94.48% of initial capacitance after 10,000 cycles, which are good electrochemical performances among aqueous electrolytes for green and new efficient energy storage devices.