Perovskite LaNiO3-δ oxide as an anion-intercalated pseudocapacitor electrode

Here, a novel anion-intercalated pseudocapacitive electrode, perovskite LaNiO3 oxide, was synthesized using sol-gel method and investigated systematically by measuring its CV and GCD curves in KOH electrolyte. XRD, SEM, HRTEM and XPS were employed to characterize the phase composition, microstructure and surface chemistry of LaNiO3 powders, respectively. Results show that LaNiO3 has excellent pseudocapacities with the specific capacitance of 478.7 F g−1 at 0.1 mV s−1, and a good cycling stability of reducing 5.5% charge-discharge efficiency after 15000 cycles. Oxygen intercalation and extrusion mechanism of the LaNiO3 electrode is also revealed that charge storage in this kind of perovskite pseudocapacitor electrode is associated with the intercalation of oxygen-ion into oxygen vacancies, which is mainly originated from the variation of different valence states of B site Ni in perovskite ABO3 structure.