Silver decorated lanthanum calcium manganate for electrochemical supercapacitor

Abstract

Perovskite La _0.5 Ca _0.5 MnO _3 (LCM) based materials are promising for electrode construction but their poor conductivities often lead to limited electrochemical performances. In this work, LCM was combined with Ag through the two-step process based on sol-gel and silver mirror reaction. The as-obtained LCM@Ag composites were characterized by scanning electron microscopy and x-ray powder diffraction. The mass percent determined by energy disperse spectroscopy combined with x-ray photoelectron spectroscopy was estimated at 5%. The electrochemical measurements showed LCM@Ag to possess superior specific capacitance of 287 C g ^−1 (179 F g ^−1 ) at 1.5 A g ^−1 while pure LCM delivered only 187 C g ^−1 (117 F g ^−1 ). The key to the improvement of performance can be attributed to the silver nanoparticle introduction, which leads to the enhancement of the electron transport capacity and ion diffusion for the composite. Meanwhile, the cycle stability slightly improved and the retention rate after 3,000 cycles at 10 A g ^−1 reached 66%. In sum, La _0.5 Ca _0.5 MnO _3 perovskite system looks promising for electrode construction, where silver modification could improve the overall electrochemical properties.

Keywords

• supercapacitor
• perovskite
• LaMnO3
• Ag nanoparticle
• composites