One-pot electrochemical synthesis of ultrathin trimetallic Mn-Sn-Co oxide coral-like nanostructure as free-standing active electrode material for energy storage applications

Abstract

The present study proposes a facile and controllable approach for the design and fabrication of an ultrathin binder-free trimetallic oxide nanostructure on nickel foam as an efficient hybrid supercapacitor. The morphological and physicochemical characteristics of the as-prepared Mn-Sn-Co-1 oxide (MSCO-1) electrode were validated using various techniques. The integrated MSCO-1 electrode displayed a high area-specific capacitance of 4.15 F cm−2 at 1 A g−1, good rate capability, and excellent cycling stability of 92.9 % capacitance retention after 3000 CD cycles in a three-electrode system. Its superior electrochemical performance is related to the distinctive coral-like morphology with a hierarchical porous network structure and synergistic effects of the multi-component metal oxides, effectively improving the electroactive sites and assisting the ease penetration of both electrolyte ions and electrons. Likewise, the corresponding asymmetric supercapacitor (ASC) was successfully fabricated by assembling MSCO-1 and activated carbon (AC) as cathode and anode, respectively, exhibiting a high energy density of 39.6 Wh kg−1 at 800 W kg−1 along with superior cycling stability. Moreover, the asymmetric supercapacitor suggests a good state of health with a small leakage current and low self-discharge, which can maintain 1.2 V of its initial voltage (1.6 V) after eight hours of self-discharge test. We also demonstrated the illumination of a yellow LED indicator for more than 480 s. These exciting results render that the MSCO-1 nanostructure could be a promising electrode in developing energy storage systems for feasible applications.