Porous lanthanum doped NiO microspheres for supercapacitor application

► Formation of porous structure of La3+-doped NiO via a hydrothermal method. ► Exhibited high specific surface area (277.5 m2 g−1) and large pore volume (0.79 cm3 g−1) of La3+-doped NiO spheres. ► Composite has high specific capacitance (253 F g−1), and good cycling stability over 500 cycles.