Morphological evolution and electrochemical properties of MZCO-0.3 regulated by non-variable valence ions

The enhancement of the electrochemical performance of supercapacitors can be accomplished by the successful construction of battery electrode materials with suitable structures, morphologies, specific surface areas, and electrical contact with the electrolyte. The spinel structure of the double transition metal ZnCo2O4 is easy to modify. In this study, MZCO-0.3 ternary transition metal oxides with superior morphologies, good contact with electrolyte, and a large specific surface area were successfully synthesized by the hydrothermal method. Specifically, the three-dimensional dandelion ternary MZCO-0.3 metal oxide is a dispersed needle-like cluster with a large open void, a good aperture, and a specific surface area, and is a suitable material for supercapacitors. The MZCO-0.3 electrode achieves an extraordinary specific capacity of 1225C g−1 at 1 A g−1 and exhibits good cyclic stability (108 % capacity retention rate) after 5000 cycles. Moreover, the prepared MZCO-0.3//AC hybrid supercapacitor (HSC) has good cycling performance and energy density. The capacitance retention rate is 85 % after undergoing 20,000 cycles, and the coulombic efficiency is nearly 100 %. When the power density is 849.97 W kg−1, the energy density is 64.22 Wh kg−1. It is impressive that when the power density is 8500.8 W kg−1, the energy density is still retained at 35.42 Wh kg−1. These results demonstrate the promising application potential of the MZCO-0.3 synthesized in this study as electrode materials for supercapacitors. Based on MZCO-X (X = 0.1, 0.2, 0.3, 0.5 and 0.8) ternary transition metal oxide，a positive active material with stable structure, good morphology and electrochemical performance was established. [Display omitted] •The ZCO with good morphology and electrochemical properties was constructed.•The morphology and surface of MZCO-X was regulated by non-variable valence elements.•The MZCO-0.3 has good electrochemical performance by non-variable valence ion mixing.