All-organic PVDF-based composite films with high energy density and efficiency synergistically tailored by MMA--GMA copolymer and cyanoethylated cellulose.

All-organic polymer dielectric films have been widely used for different electrical devices in recent years. However, their development is impeded by low and large device volume. In the present paper, polyvinylidene fluoride (PVDF) composite dielectric materials, with high energy density () and energy efficiency (), were prepared through the synergistic effect of a new MMA--GMA (MG) copolymer and cyanoethylated cellulose. MG was miscible with PVDF, which reduced the dielectric loss (tan ) and improved the of PVDF due to the linear structure and the hydrogen bonding interaction with the epoxy groups for MG. To further enhance the of the dielectric films, cyanoethylated cellulose (CR-C) was added as a third component into the PVDF composite matrix to improve the . The deep trap effect of hydrogen bonds between PVDF/MG and CR-C improved the electric breakdown strength () of the three-phase composite films from 440 MV m to 640 MV m. Moreover, the high polarization of cyanoethylated cellulose can significantly improve the (24.43 J cm) of the three-phase composite dielectric film, and the efficiency can be maintained above 75% at 640 MV m. This research provides a new idea for the manufacturing of homogeneous and stable all-organic PVDF dielectric composite films based on the hydrogen bonding construction strategy.