Facile Synthesis of LaCoO₃ with a High Oxygen Vacancy Concentration by the Plasma Etching Technique for High-Performance Oxygen Ion Intercalation Pseudocapacitors

Abstract

The content of oxygen vacancy, as the intercalation places of oxygen during the oxygen ion intercalation process, has a significant influence on the electrochemical properties of the perovskite pseudocapacitance. To enhance the electrochemical performance of perovskite supercapacitors, we propose a novel strategy of the plasma etching technique to improve the oxygen vacancy concentration of the LaCoO3 electrode. The influence of plasma composition and etching time on the etching effect was investigated. Results show that the etching effect of H2 is better than that of Ar. The specific capacitance of the LaCoO3 electrode etched for 5 min in 10 sccm H2 and 90 sccm Ar increased from 339.8 F g–1 to 706.9 F g–1. The asymmetric supercapacitor assembled with graphene oxide delivers a high energy density of 47.64 Wh kg–1 at a power density of 804.4 W kg–1 and still maintains 35.02 Wh kg–1 at a high power density of 37 080 W kg–1. After 4000 cycles at 5 A g–1, there is little degradation of specific capacitance with the Coulombic efficiency maintaining a high level of 96%. It can be concluded that the plasma etching technique is an efficient way to improve the energy storage performance of perovskite pseudocapacitive materials.

Interconnected network‐like single crystalline bimetallic carbonate hydroxide nanowires for high performance hybrid supercapacitors

“…The obtained results are higher or even comparable than those of the previous reports (Table S1). 23,25,29,35,[39][40][41][42][43][44][45][46][47][48][49]…”

Experimental study on the degradation mechanism of LaCoO3-based symmetric supercapacitors

“…And the micro morphology of samples is shown as nanoparticles with irregular surface with a size of 30-100 nm. 43 The BET specic surface area and pore size distribution can be obtained by N 2 adsorption/desorption experiments. Fig.…”

“…The energy storage mechanism of LaCoO 3 electrode in the KOH electrolyte is oxygen ion intercalation mediated through oxidation of cobalt centers. 16,50 The equation is as follows, 43 La…”

“…84-0848) of rhombohedral perovskite structure LaCoO 3 and there are no impurity obvious peaks corresponding to other phases, which indicates that the prepared samples are single phase LaCoO 3 powders. And the micro morphology of samples is shown as nanoparticles with irregular surface with a size of 30-100 nm 43. The BET specic surface area and pore size distribution can be obtained by N 2 adsorption/desorption experiments.…”

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

“…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.…”