Advanced Pseudocapacitive Performances of a Ti3C2Tx–ZnOHF/ZnO Nanocomposite for Energy Storage Applications

Abstract

The growing demand for efficient and high-performance energy storage systems is driving the exploration of novel materials and composites. Traditional electrode materials often face limitations in terms of energy and power densities. This article demonstrates a novel spray-coated cathode electrode system composed of Ti3C2Tx MXene and zinc hydroxy fluoride/zinc oxide nanostars for energy storage applications in a neutral pH electrolyte (1M Na2SO4), thus avoiding corrosion problems related to water splitting reactions. Optimized Ti3C2Tx-nanostar electrodes exhibit superior specific capacitance, achieving 236 F g−1 at 5 mV s−1 in cyclic voltammetry and 139 F g−1 at 5 mV s−1 in galvanostatic charge–discharge measurements, which is superior to pure Ti3C2Tx (115 F g−1 at 0.5 A g−1) and pure nanostar (108 F g−1 at 0.5 F g−1) electrodes, used as reference. Additionally, an asymmetric Ti3C2Tx||Ti3C2Tx-nanostars supercapacitor device achieves a specific capacitance of 147 F g−1 at 0.5 A g−1, an energy density Ed ≈ 46 W h kg−1 at a power density Pd ≈ 875 W kg−1, and the highest Pd ≈ 16 650 W kg−1 at Ed ≈ 14 W h kg−1. These findings demonstrate that zinc oxide nanostars combined with delaminated Ti3C2Tx MXene hold a significant promise for efficient energy storage applications, leveraging the synergy between double-layer capacitance and pseudocapacitive effects.