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Supercapacitors' effective short-term power delivery has garnered a lot of attention; however, they face challenges in terms of stability and capacity. Promising possibilities for enhancing supercapacitor performance are nanocomposites with reduced ion/electron diffusion routes and increased specific surface areas. Hence, this study focused on the fabrication and electrochemical performance of supercapacitor electrodes made of NiO@TiO2nanocomposites, addressing a gap in the literature on NiO nanoparticles (NiO NPs) loaded with TiO2nanofibers. The presence of Ni2+, Ni3+, and -OH functional groups was detected using X-ray photoelectron spectroscopy (XPS), and the elements presence was reiterated by energy-dispersive X-ray spectroscopy (EDS). Scanning electron microscopy (SEM) in addition to transmission electron microscopy (TEM) elucidated the morphological concepts, demonstrating width as 72 nm for NiO NPs and the length of the TiO2nanofibers ranging between 300 and 500 nm. An exceptional specific capacitance of 750 F·g−1@3 A·g−1was demonstrated by NiO@TiO2electrodes, with reasonable cyclic reliability (94.6 %@15 A·g−1) post 10,000 galvanostatic charge–discharge (GCD) cycles. At 1.9 A·g−1current density, NiO@TiO2– two electrode arrangement generated a significant amount of energy density, 54.29 Wh·kg−1@ 4446 W·kg−1power density along with a competent cyclic stability post 10,000 cycles. We also employed a self-analyzed monolayer (SAM) approach to assess cyclic voltammetric (CV) response by utilizing a coupled simulation of the Butler–Volmer and Nernst–Planck–Poisson (N-P-P) models through finite element modeling in COMSOL. The results obtained suggest that NiO@TiO2electrodes have excellent electrochemical traits indicating that they are commendable nanocomponents for applications involving advanced energy storage.

Zn-ion hybrid supercapacitors (ZHSCs) with high power and energy density have great potential in energy storage applications such as hybrid vehicles and renewable energy storage. However, the large radius of hydrated Zn2+-ions hampers their efficient storage in micropores with limited pore sizes, resulting in limited weight ratio capacitance and poor rate capability of ZHSCs. In this study, we developed the novel N-doped and oxygen vacancy-rich CCO nanowires (N-Ov-CCO@CC) architecture with the help of Chemical Vapor Deposition (CVD). Due to the guiding synergy of N-doping, defects, and surface engineering, N-Ov-CCO@CC exhibits significantly enhanced electrochemical performance. The N-Ov-CCO@CC single electrode exhibits excellent charge storage properties, including a high capacitance of 1480.7 F/g at 1 A/g, excellent rate-capability (88.4 % at 20 A/g), and excellent cycle stability of up to 90.1 % for 5000 cycles. The charge storage mechanism was analyzed by ex-situ XRD and XPS, and it reveals that the pseudocapacitive charge storage characteristics are dominant. Operating in the potential range of 1.2–2.0 V, the N-Ov-CCO@CC//Zn-ZHSC provides a high capacitance of 308.2 F/g at 1 A/g, excellent rate capability (86.9 % at 10 A/g), long lifetime (97 % after 10,000 cycles), and high specific energy/power (134.32 Wh/kg at 9507.6 W/kg). Density function theory (DFT) validations show that the N-Ov-CCO system possesses higher conductivities than Ov-CCO and pristine CCO. This work provides an effective strategy for constructing multifunctional electrochemical energy materials for ZHSCs.