Binder-Free Phosphorus-Modified Multiphase Ni-Co Sulfide Nanoarchitectures with Sea-Urchin Morphology for High-Capacity Hybrid Supercapacitors and Practical Applications.

Owing to the high demand for advanced energy storage, the exceptional characteristics of transition metal sulfides have attracted great interest from researchers. Herein, phosphorus (P)-encapsulated nickel-cobalt sulfides (NCSs) prepared via a hydrothermal process and phosphorized in a tube furnace to produce P@NCS (with 20 mM sulfur source) are reported. The P@NCS material is synthesized through a meticulous multistep process, ensuring precise control of its material properties. Successful incorporation of P significantly enhances the electrochemical performance of the electrode. The electrochemical evaluation demonstrates the superior performance of the P@NCS electrode. Cyclic voltammetry and galvanostatic charge-discharge curves reveal enhanced oxidation/reduction behavior and high areal capacity. Electrochemical testing shows high redox reactions and decreased electrode-electrolyte resistance, and the P@NCS electrode can last for over 10000 cycles. A hybrid supercapacitor (HSC) constructed with P@NCS and activated carbon/nickel foam electrodes exhibits a specific capacitance of 95.93 F g at 3 mA cm. This HSC device demonstrates outstanding cycling stability, and it can efficiently store solar energy and continuously power electronic devices. This work emphasizes the potential of P@NCS electrode materials in advanced energy storage systems and provides a systematic and simple synthesis procedure with important implications for sustainable energy applications.