Ruddlesden-Popper type La2NiO4+δ oxide as a pseudocapacitor electrode

Ruddlesden-Popper type La2NiO4+δ (LNO) oxide was investigated as a novel pseudocapacitive electrode and performed high performance with the capacitance of 657.4 F g−1 under the scan rate of 2 mV s−1 in 3 M KOH electrolyte. Two cathodic peaks and one anodic peak in CV curves of LNO in KOH electrolyte indicate the special oxygen insertion/extrusion processes because its structure alternates with perovskite LaNiO3 layers and LaO rock-salt layers in succession. Cycle performance of LNO at a relatively high current density of 10 A g−1 is approximately 96.2% after 500 cycles in 3 M KOH electrolyte, showing good cycling stability. This confirms LNO as a potential candidate for high performance pseudocapacitor electrodes.