The performance enhancement of the cascaded thermal energy storage system was investigated using multi-wall carbon nanotubes (MWCNT) in phase change material (PCM) with and without a stratifier at the tank's charging inlet. The circular dispersion introduced by the stratifier into the intake of the charging tank. The experimental tests were conducted with inlet temperatures of 70, 75, and 80 °C and rate of flow 1, 2, and 3 l/min. According to the analysis findings, employing the stratifier in the storage tank resulted in an effective charging time of 37 min and 50 min without the stratifier. Also, a thermogravimetric analysis (TGA) was done to determine the material's stability. In comparison to the cylindrical phase PCM capsule, the spherical phase PCM capsule had higher total energy and enthalpy, and the spherical phase PCM capsule's heat flow contours were uniform.