▎ 摘　　要

This study demonstrates a one-step and environmental friendly method to fabricate graphene/nickelous hydroxide (GO/Ni(OH)(2)) hybrid filler via hydrothermal strategy for dielectric polymer composites based on PVDF. Ni(OH)(2) nanosheets are grown uniformly on the surface of GO sheets, such hybrid filler can bring a number of advantages for resulted composites: 1. Ni(OH)(2) could reduce the dielectric constant contrast between graphene and PVDF; 2. The special structure of such hybrid filler could lead to enhanced breakdown strength; 3. Strong interfacial interaction between filler and matrix could be achieved due to the hydroxyl groups on the surface of such hybrid filler. As a result, 1.25 wt% of such hybrid filler leads to dielectric constant of 12.05 at 10(3) Hz for the final composites, which is higher than neat PVDF (approximate to 9.6). While the tans is limited at 0.011 which is much lower than GO based composites. And the breakdown strength is 254 kV mm(-1), an enhancement of 20.9% over neat PVDF. More importantly, an energy density of 3.89 J cm(-3) can be achieved, with an enhancement of 2.6 times over GO/PVDF (1.47 J cm(-3)) and 1.57 times over neat PVDF (2.47 J cm(-3)). Furthermore, this study provides a one-step environmental friendly method for the fabrication of functional filler for various functional polymer nanocomposites.