Dielectric properties and thermal conductivity of core-shell structured Ni@NiO/poly(vinylidene fluoride) composites

To suppress the high loss of nickel (Ni)/poly(vinylidene fluoride) (PVDF) while remaining high dielectric constant (k) near the percolation threshold. In this study, core-shell structured Ni (Ni@NiO) particles were prepared by heat treatment of raw Ni powder under air atmosphere and incorporated into PVDF to prepare Ni@NiO/PVDF dielectric composites. The morphological, dielectric properties and thermal conductivity of the composites are characterized. The results indicate that compared with the raw Ni reinforced PVDF composites, the Ni@NiO particles endow PVDF with a high-k and rather low dissipation factor owing to the presence of NiO shell between Ni core and PVDF which serves as an interlayer between the Ni cores preventing them from contacting with each other. Additionally, the Ni@NiO/PVDF composites still possess a high thermal conductivity. Therefore, the as-prepared Ni@NiO/PVDF composites possess high-k but low loss, high thermal conductivity, making them promising for the industrial application as embedded capacitors.