Dielectric micro-capacitance for enhancing piezoelectricity via aligning MXene sheets in composites

Piezoelectric polymers have attracted a great deal of attention for flexible electromechanical applications but still suffer from low piezoelectric coefficients (∼−24 pC/N) in commercial films. Here, we propose a dielectric micro-capacitance strategy to enhance piezoelectricity via texturing well-aligned MXene (Ti3C2Tx) sheets into a poly(vinylidene fluoride) (PVDF) matrix using a scalable blade-coating technique. This aligned MXene/PVDF composite presents a piezoelectric coefficient of −63.3 pC/N due to its improved permittivity. More importantly, a modified model of the piezo-composite is put forward to further understand the interfacial polarization and dielectric relaxation effect in this percolation system for designing piezo-composites with better performances. Notably, this work might motivate new design principles and approaches to regulate electric behavior and promote piezoelectricity in electroactive polymers.