The Interwoven Structured Two-Dimensional NiCo Layered Double Hydroxide Tortuous Nanosheet as Performance-Enhanced Electrode Material toward Battery-Type Supercapacitor

Abstract

Implementing a rational structure and leveraging unique components are crucial to advancing high-performance supercapacitors (SCs) and essential to unlocking their full potential. Herein, we successfully developed a facile solvothermal synthetic approach for fabricating NiCo-layered double hydroxide (NCLDH) nanosheets for high-performance supercapacitor applications. NCLDH nanosheets were synthesized with precise control over their morphology and size by optimizing the H₂O-to-DMF ratios. Besides, the correlations between the proportion of the solvent and the resulting properties of the NCLDHs were analyzed. The formation of unique vertical orientation nanosheets of interwoven structures was observed in NCLDH-21, where the ratio of H₂O and DMF was 2 : 1. The resulting nanosheets display unique characteristics that distinguish them from other NCLDH materials. The synthesized NCLDH-21 nanostructures had many benefits, including increasing the number of active sites that could be used for redox reactions, facilitating the efficient collection and transport of electrons and ions, and reducing aggregation, which effectively stabilized the volume variation of active matter during cycling. The NCLDH-21 nanosheets were optimized to exhibit a remarkable specific capacitance of 2,054 F g⁻¹ at 1 A g⁻¹ and exceptional rate capability. The assembled hybrid SC (HSC) achieved an impressive energy density of 67.67 Whr kg⁻¹, demonstrating remarkable cycling stability. Hence, the remarkable electrochemical outcomes of NCLDH-21 nanosheets demonstrate their immense potential as a cost-effective electrode material for next-generation energy-storage devices.