Polymer ceramic nanocomposites exhibit performance characteristics superior to those of the parent materials as they harness the mechanical properties of the polymer and the dielectric properties of the ceramic. However, the rational design of flexible high-k dielectric nanocomposites with high filler loading is still challenging as the increase of the ceramic content deteriorates the mechanical properties of the nanocomposites. In this work, we investigated the fabrication of flexible electronics by dispersing BaTiO3 (BTO) colloidal nanocrystals with various sizes (10-20 nm) into the styrene butadiene styrene (SBS) matrix. The resulting SBS-BTO nanocomposite films contain up to 50% (weight) BaTiO3 nanocubes fillers and possess high energy density values along with excellent mechanical properties. It has been observed that the nanocomposite films can easily be peeled off from any type of substrate which is an indication of good flexibility and strength of these free standing films. We observed a linear increase in the dielectric constant with respect to fillers content, ranging from 6.1 to 24.1 for 0% to 40% respectively. The alternate current (AC) conductivity of the polymer remained below 10-8, which shows the polymer is insulative and can be used in flexible capacitor applications. Also, with scanning electron microscope, we observed that, the BTO cuboidal nanocrystals are uniformly distributed in the polymer matrix that can explain the reason behind of good flexible property of the film. The experimental results show that these nanocomposite thin films exhibit superior properties which make them attractive for implementation in high-performance capacitive storage devices, wearable technology and nanoelectronics.