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

Abstract

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.

Symmetric/asymmetric energy storage device of reduced graphene oxide assisted LaNi0.9Co0.1O3 perovskite nanomaterials

“…202), ( 024), ( 116), (300), ( 214), ( 220), ( 208), ( 134) and (128), respectively. The X-ray diffraction data indicate the formation of a highly pure crystalline phase without any impurity [11,23].…”

“…Perovskite materials are providing significant response in terms of specific capacitance, energy density, power density and long-life cycle retention for electrochemical supercapacitors [6][7][8]. The charge storage mechanism executes in electrochemical supercapacitor through two reactions; electrochemical double layer capacitor (EDLC) store energy via separation of charge and accumulation of charge at the interface of the electrode/electrolyte; pseudocapacitance which store energy via redox (reduction, oxidation) process and ion intercalation during electrochemical reaction [9][10][11][12][13]. The mechanism involved during electrochemical reaction is shown in Scheme 1.…”

Morphological Impact of Perovskite-Structured Lanthanum Cobalt Oxide (LaCoO3) Nanoflakes Toward Supercapacitor Applications

“…16 Zhang et al explored the electrochemical properties of Sr-doped LaCoO 3 and LaCoO 3 /rGO composites, achieving a specific capacitance of 416 F g −1 at a 1 A g −1 current density. 31 Similarly, Cao et al investigated the electrochemical performance of Sr-substituted perovskite-type LaCoO 3 in both symmetric and asymmetric two-electrode assemblies using a Na 2 SO 4 electrolyte. They achieved an energy density and a power density of 27.7 Wh kg −1 and 500 W kg −1 , respectively.…”

La1–xKxFeO3−δ: An Anion Intercalative Pseudocapacitive Electrode for Supercapacitor Application

“…Perovskite oxides have the unit cell formula ABO 3 , where the A-site is either an alkaline or lanthanide element, while the B-site is a transition metal element. By strategically selecting the A-site elemental composition, one can readily control the B-site element’s oxidation state as well as the overall oxygen vacancy content via charge compensation. , Perovskite supercapacitors have attracted widespread attention, and several perovskites such as LaNiO 3 , LaFeO 3 , La x Sr 1– x CoO 3−δ , La x Sr 1– x Cu 0.1 Mn 0.9 O 3−δ , Sr 2 CoMoO 6−δ , and La 0.85 Sr 0.15 MnO 3 were investigated for pseudocapacitance applications.…”

“…20,21 Perovskite supercapacitors have attracted widespread attention, and several perovskites such as LaNiO 3 , 22 LaFeO 3 , 2323 La x Sr 1−x CoO 3−δ ,24 L a x S r 1 − x C u 0 . 1 Mn 0 .…”