Chemical-looping combustion (CLC) is a very promising technology to combine the energy-utilization situation in China and CO2 zero-emission in situ allowing for CO2 sequestration by efficient and energy-saving ways and without nitrogen oxide (NOx) formation. Having an oxygen carrier with sufficient reactivities in reduction and oxidation and enough recyclability and strength for long-term operation is one of the key issues of the CLC process. This paper focuses on the investigation of Ni-based oxygen carriers for CLC by coal char. First, Al(OC3H7)(3) and Ni(NO3)(2) are selected as the main raw materials to prepare sol-gel-derived NiO/NiAl2O4 oxygen carriers. The oxygen carrier with a mass content of 60% NiO, a sintering temperature of 1300 degrees C, and a sintering time of 6 h performs comparatively well. Second, the reduction reaction of the NiO/NiAl2O4 oxygen carriers with char and the circular reduction/oxidation reactions of the NiO/NiAl2O4 oxygen carriers with char/air or hydrogen/air are carried out in a thermogravimetric analysis (TGA) instrument to investigate the reactivities and chemical life of the prepared NiO/NiAl2O4 oxygen carriers. The experimental results show that (a) when the TGA temperature is higher than 850 degrees C, NiO/NiAl2O4 starts to react with coal char rapidly, which indicates that CLC of coal char using NiO/NiAl2O4 as oxygen carriers is a feasible technology of energy utilization in principle; (b) NiO/NiAl2O4, which maintains its activity over single-cycle reduction/oxidation reactions with char/air or multiple-cycle reduction/oxidation reactions with hydrogen/air, exhibits extremely good recyclablity; (c) the porous beehive structure of the NiO/NiAl2O4 particle is maintained, and the sintering behavior between different particles is not observed during cyclic studies. Those experimental results prove the sol-gel-derived oxygen carrier NiO/NiAl2O4 is capable of being used in chemical-looping combustion fueled by coal char or H-2.