Microwave hydrothermal synthesis of urchin-like NiO nanospheres as electrode materials for lithium-ion batteries and supercapacitors with enhanced electrochemical performances

• Urchin-like NiO nanospheres were synthesised by a microwave hydrothermal method.
• The NiO nanospheres consist of nanocrystals and porous structure.
• NiO nanospheres exhibited a high reversible specific capacity of 1027 mA h g−1.
• The NiO nanospheres also delivered a high supercapacitance of 736 F g−1.

Urchin-like NiO nanospheres were synthesised by a microwave hydrothermal method. The as-synthesised NiO nanospheres were characterised by X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. It was found that NiO nanosphere consists of a nanoporous structure and nanosize crystals. When applied as anode materials in lithium-ion batteries, NiO nanospheres exhibited a high reversible specific capacity of 1027 mA h g−1, an excellent cycling performance and a good high rate capability. NiO nanospheres also showed a high specific capacitance as electrode materials for supercapacitors.