NiAlP@Cobalt substituted nickel carbonate hydroxide heterostructure engineered for enhanced supercapacitor performance

Two-Dimensional Synergistic Interfacial Orientation on Tin Oxide-Reinforced Cobalt Carbonate Hydroxide Heterostructures for High-Performance Energy Storage

A hierarchical cobalt carbonate hydroxide (CCH) nanostructure with outstanding electrochemical kinetics and structural stability for energy storage is largely unknown. Herein, we report tin oxide-functionalized CCH surface-enabled unique two-dimensional (2D) interlayered heterostructures that promote high conductivity with more electroactive sites to maximize redox reactions. A simple electrodeposition technique was utilized to construct the hierarchical 2D CCH electrode, while a surface-reinforced method was employed to fabricate the 2D interlayered SnO on CCH. The fabricated SnO@CCH-8 electrode showed a maximum areal capacity of 720 mC cm-2 (specific capacitance of 515 F g-1) at a current density of 1 mA cm-2 in 3 M KOH electrolyte. The obtained results indicate that the synergetic effect of SnO in the CCH network delivers an efficient charge transfer pathway to achieve high-performance energy storage. Moreover, SnO@CCH-8//AC was devised as a hybrid supercapacitor (HSC), ensuring a maximum specific capacitance of 129 F g-1 and maximum specific energy and power of 40.25 W h kg-1 and 9000 W kg-1, respectively, with better capacitance retention (94%) even beyond 10,000 cycles. To highlight the excellent performance in real-time studies, the HSC was constructed using a coin cell and displayed to power 21 light-emitting diodes (LEDs).

Towards High-Performance Supercapacitor Electrodes via Achieving 3D Cross-Network and Favorable Surface Chemistry

Transition metal phosphides/phosphates (TMPs) are considered appealing electrode materials in energy-related fields, especially in supercapacitors. However, the dilemma of inadequate electrode kinetics and dimensional unreliability evoked by a huge volume variation during cycling significantly plagues their progress. To mitigate this issue, in this work, a 3D cross-network in situ assembled via self-derived N-doped carbon hybrid Ni-Co-P/POx 2D sheets is fabricated. Particularly, high-Fermi-level N-doped carbon well confines Ni-Co-P/POx nanoparticles at the molecular level, and N-doping leads to redistribution of spin/electron density in the carbon skeleton, effectively regulating the electron environment of nearby Ni-Co-based moieties, resulting in a relatively lower surface work function, as known via experimental and Kelvin probe force microscopy (KPFM) results, which favors electron flee from the electrode surface and facilitates electron transport toward a rapid supercapacitor response. Moreover, the well-defined 3D cross-network architectures featured with in-plane pores and interconnected with each other can provide more ion/electron transfer pathways and 2D sheets with excellent surface chemistry available for sustainable ion/electron mobility, synergistically affording the favorable electrode kinetics. Accordingly, the resultant Ni-Co-P/POx@NC electrode shows admirable specific capacitance, excellent rate survivability, and long-term cyclability. The as-assembled asymmetric device exhibits remarkable energy and power outputs (48.5 Wh kg^-1 and 7500 W kg^-1), superior to many reported devices. Furthermore, our devices possess the prominent ability to power a commercial electronic thermometer for 1560 s at least, showcasing superb application prospects.