LaMnO₃/RGO/PANI Ternary Nanocomposites for Supercapacitor Electrode Application and Their Outstanding Performance in All-Solid-State Asymmetrical Device Design

The rapid growth of energy demand and lack of sustainable energy conversion/storage devices have made the supercapacitor an inevitable substitute to current storage systems. However, the major limitation to the cutting edge lies in superconductors’ relatively low energy density compared to batteries. Here, we report LaMnO3/RGO/PANI ternary composite fabricated via in situ polymerization route as an efficient electrode material with enhanced energy density. The all-solid-state designs of both LaMnO3/RGO/PANI∥LaMnO3/RGO/PANI symmetric supercapacitor and LaMnO3/RGO/PANI∥RGO asymmetric supercapacitor have been highlighted in this work. The asymmetric supercapacitor device exhibits a superior electrochemical performance (Sc = 111 F g–1 at 2.5 A g–1 and >50% retention at 20 A g–1) than a symmetric supercapacitor device although both of these devices have an appreciable electrochemical behavior. The asymmetric supercapacitor device delivers a maximum energy density of 50 Wh kg–1 at a power density of 2.25 kW kg–1. The device still delivers an energy density of 25 Wh kg–1 at a power density as high as 18 kW kg–1. It is an outstanding result among LaMnO3 based supercapacitors. In addition, the asymmetric supercapacitor device executes an excellent retention of 117% even after 100k cycles. This extraordinary performance of asymmetric supercapacitor devices favors their practical application to the current demand.