Glutaraldehyde-assisted crosslinking for the preparation of low dielectric loss and high energy density cellulose composites filled with poly (dopamine) modified MXene

In today's electric power systems, biodegradable and environmentally benign dielectric materials with outstanding dielectric capabilities are essential. Here, a hybrid filler MXene@PDA (M@P) was acquired by coating MXene with polydopamine (PDA), and then it was added into cellulose matrix to manufacture regenerated cellulose/M@P (RC/M@P) composite films. Finally, a crosslinking strategy with glutaraldehyde (GA) assistance was developed to further modify the RC/M@P composite films. The crosslinked composite films (CRC/ M@P) had a denser structure with fewer defects, considerably decreased dielectric loss, and significantly strengthened breakdown strength. The highest energy storage density of 3.37 J/cm3 was obtained for CRC/M@P1 composite film with only 1 wt% M@P at 361.07 MV/m, achieving significant enhancement compared with the original CRC film. Moreover, crosslinking also contributed to the CRC/M@P for achieving better mechanical properties. The excellent comprehensive performances endow CRC/M@P composite films with promising application for the next-generation dielectric capacitors.