Rapid and easy preparation of self-supporting La-mixed NiMoO4 nanofloral materials and their capacitance properties

Abstract

Rare earth element doped bimetallic oxides are a new technology for improving the electrochemical performance of electrode materials. In this study, 0.5% La–NiMoO₄ flower-like structured nanomaterials were directly grown on nickel-based surfaces through a fast and simple room temperature stirring method. The characterization methods such as SEM and TEM confirmed that the prepared product has a three-dimensional nanoflower-like structure, and also demonstrated that the prepared 0.5% La–NiMoO₄ nanoflower material was successfully doped with rare earth elements. We also conducted electrochemical tests on the material, and the results showed that at a reaction time of 16 h, the 0.5% La–NiMoO₄ flower-like structure exhibited excellent electrochemical performance. At a current density of 2 A g⁻¹, the specific capacitance was 2100 F g⁻¹. After 5500 cycles of charging and discharging at a current density of 1 A g⁻¹, the capacitance retention rate was 99.8%. A 0.5% La–NiMoO₄/Ni//Fe₂O₃/Ni asymmetric supercapacitor device was assembled using 0.5% La–NiMoO₄ as the positive electrode and Fe₂O₃ as the negative electrode. At a current density of 15 A g⁻¹ and a working window voltage of 1.8 V, the power density of the asymmetric device was 8000 W kg⁻¹ (energy density 56.5 W h kg⁻¹). At a current density of 5 A g⁻¹, the device underwent 5000 cycles of charge and discharge, and the capacitance retention rate was 89.5%. The 0.5% La–NiMoO₄ electrode material prepared in this study through a simple, fast, environmentally friendly method exhibits good electrochemical performance, making it a potential electrode material for development.