The strong interaction between n-eicosane and silica nanoscale skeleton exhibits novel phase change temperature management and energy utilization. In this study, a sol-gel synthesized method to fabricate phase change nano-composites by impregnating silica nano-porous materials with n-eicosane is reported. Field emission scanning electron microscope (FE-SEM) results show that the sol-gel synthesized silica has an open network structure as a host for shape stabilization of molten n-eicosane. A combined thermodynamic/heat transfer analysis was carried out to determine the total mass, thickness, and temperature excursion as a function of the area fraction of n-eicosane at given maximum energy and thermal flux. The derived hyperbolic relations showed that increasing the n-eicosane area fraction resulted in a better thermal management in smoothing temperature fluctuation, lower total mass, and lower volume in the nano-composites.