Green solvothermal synthesis of micro-/nano-structured porous β-Ni(OH)2 microspheres with enhanced electrochemical performance

Flower-like β-Ni(OH)2 microspheres have been synthesized via a PEG-assisted solvothermal process and a simple post-treatment. The result microspheres exhibit a highly porous structure with higher surface area (201 m2/g), which is beneficial to improving electrochemical properties. The morphology evolutions were well studied in detail to analyze the potential growth mechanism. While these porous hierarchical β-Ni(OH)2 microspheres were coated on the surface of nickel foam and evaluated as electrode materials, they delivered an excellent capacitance of 1401.1 F/g at 1 A/g, and 720 F/g even at a higher current density of 20 A/g. Furthermore, at a higher current density of 20 A/g, the capacitance still remains 89.0% of its initial capacitance after 1000 cycles. These results suggest that the porous β-Ni(OH)2 flower-like microsphere is a highly promising candidate for supercapacitor electrodes.