The dielectric properties of barium titanate/polyvinylidene fluoride (BT/PVDF) composites are investigated. The doped BT particles are prepared by using simple heat treatment. It is found that 1000 ℃ is the optimal temperature for the doped BT particles to improve the dielectric properties of BT/PVDF composites. Besides, we also find that the breakdown strength of the BT/PVDF composites can be significantly enhanced when the surface of the doped BT particles are pre-modified with phthalic acid or KH550. In particular, the BT/PVDF composites doped with KH550 modified BT particles have the maximum energy storage density of 4.08 J/cm3, which is 81.33 % higher than that of BT/PVDF composites doped with BT particles and without any treatment. Therefore, we can conclude that heat treatment and surface modification of doped BT particles could become new approaches to enhance the energy storage performance of the BT/PVDF composites, which has a good application prospect in the field of dielectric energy storage materials.

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