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Morphologically engineered porous electrodes show great promise in energy applications as they exhibit improved electrochemical activity owing to increased electrical conductivity, increased surface area, and a shorter path length for ion transport. Herein, the role of precursors (chlorides, acetates and nitrates) on the crystallinity and textural features of Nickel Cobaltite, obtained by the controlled precipitation through hydrothermal synthesis, is studied. The synthesis yielded urchin like structures with morphological variations in substructures based on the precursor anion types. The surface area values obtained for nickel cobaltite derived from the chloride (NCO‐C), nitrate (NCO‐N), and acetate precursors (NCO‐A) were 30,110 and 115 m2 g−1, confirming the influence of anions on the textural features. The time dependant electrolyte (2 M KOH) infiltration behaviour on the electrode surfaces based on contact angle measurements is invoked to correlate its morphological and textural attributes with the electrolyte transport kinetics. The electrochemical performances were derived from cyclic voltammetry, galvanostatic charge discharge analysis and impedance measurements. The electrolyte infiltration studies established a dependence on the precursor anion. NCO‐A facilitated faster electrolyte infiltration time of 7800 ms compared to 16200 ms and 54,000 ms for NCO‐N and NCO‐C electrodes, respectively. Furthermore, NCO‐A exhibited a greater specific capacitance of 802 F g−1 than NCO‐N (500 F g−1) and NCO‐C (342 F g−1). The morphology modulation coupled with optimal porosity led to conducive pathways for reversible electrolyte infiltration resulting in increased capacitive contribution in NCO‐A. The study revealed that the size of intercalating anions exercised a significant impact on the morphological and electrochemical features, signifying the importance of synthetic approaches in determining the functional properties of electrode materials. [ABSTRACT FROM AUTHOR]

Self-supported NiCo2O4–NiCoO2 sheathed architectures on nickel foam (NCO-nco/NF), obtained by a two-step hydrothermal, postcalcination treatment, are demonstrated to be an efficient battery-type electrode for supercapacitors. NiCoO2 nanosheets uniformly extend over the NiCo2O4 urchin resulting in a synergistic association wherein the intrinsic redox ability of the scaffold and the sheath's superior hydroxyl adsorption capacity enabled enhanced electrochemical performance compared to a reverse architecture (nco-NCO/NF). Moreover, the NCO-nco/NF composite electrode with a favorable meso–macro porosity gave a high specific charge of 1373 C g–1 (1961 F g–1) with appreciable endurance in KOH electrolyte (5000 cycles). Additionally, an NCO-nco/NF and activated carbon hybrid supercapacitor assembly demonstrated a high energy density of 66.6 W h kg–1 at a power density of 400 W kg–1. The unique electrode design combining the individual attributes of the constituent units offers the possibility of developing high-performing electrode materials for supercapacitor applications. [ABSTRACT FROM AUTHOR]