Spherical architectures of nickel-aluminum layered double hydroxide (NiAl-LDH) with hydrotalcite-like nanoflakes as building blocks were facilely fabricated by precipitation reaction in aqueous solution without any surfactants and organic solvents. Growth of such unique structure undergoes preorganization of primary nanospheres of colloidal amorphous aluminum hydroxide (AAH) in solution, followed by nucleation and crystallizaion of LDH from exterior to interior of AAH spheres by an in situ transformation mechanism. The structure and morphology of LDH spheres depend on both starting raw materials and synthetic parameters including reaction time, reaction temperature, and aqueous ammonia dosage. NiAl-LDH sphere as positive electrode material delivers improved rechargeable and discharge capacity, with the highest discharge capacity of 173 mAh g(-1) at a current density of 30 mA g(-1) within a potential range from -0.1 to 0.45 V in 10 mol L-1 KOH solution, due to the faster diffusion processes in the spherical architecture than the powder sample. (c) 2014 American Institute of Chemical Engineers AIChE J 60: 4027-4036, 2014