Nickel hydroxide as novel filler for high energy density dielectric polymer composites

Abstract The preparation of high performance dielectric polymer composites often involves methods which are quite difficult to be used for large scale application due to their complexity. To tackle this, current study demonstrates a novel type of dielectric filler for the preparation of high performance dielectric composites: Ni(OH)2. Due to the abundant OH groups on their filler surface, hydrogen bond is observed between Ni(OH)2 and PVDF matrix, and beta form crystal of PVDF is induced. Among 0D, 2D and 3D Ni(OH)2, the platelet 2D Ni(OH)2/PVDF composite illustrates the highest dielectric constant (16.3), breakdown strength (421 kV/mm) and energy density (17.3 J/m3) with as little as 5 wt% (3.02 vol%) Ni(OH)2 in PVDF matrix. Such value is rather large comparing with many literature results. More importantly, this method does not involve any filler surface modification. Moreover, finite element simulations indicate that the distribution of electric field and energy density for composites containing platelet like Ni(OH)2 is more uniform than the rest, which should be the mechanism for enhanced dielectric performances. This provides a novel type of filler for the preparation of high performance dielectric polymer composites.