Flexible Integrated Self‐Charging Capacitor System with High Power Density Enabled by Mechanically Nanostructured Ferroelectric

ABSTRACT We report a flexible self‐charging capacitor system that integrates a triboelectric nanogenerator (TENG) with a flexible Pb(Zr x Ti 1 ‐ x )O 3 (PZT) ferroelectric ceramic capacitor by aerosol‐deposition (AD). The flexible PZT capacitor demonstrated high energy storage capabilities, achieving a recoverable energy density of 35.8 J cm − 3 under an applied electric field of 2000 kV cm −1 , as determined from the measured polarization‐electric field (P‐E) hysteresis curve. To enhance triboelectric performance, a micro‐imprinting process is applied to the Al surface in the TENG, improving the contact surface area and output performance. Using biomechanical tapping as an input, the TENG produced a rectified open‐circuit voltage of 350 V, corresponding to an electric field of 1000 kV cm −1 across the PZT capacitor. The flexible self‐charging PZT capacitor exhibited a recoverable energy density of 5.9 J cm −3 and a discharge power density of 16.0 MW cm −3 . This improved power density is achieved through the combination of a simple micro‐patterning technique on the TENG and the annealing of the AD PZT film, which induced a slim ferroelectric P‐E hysteresis behavior. Our results suggest that this flexible self‐charging system holds significant promise for powering next‐generation flexible smart devices and high‐power electronics, offering a scalable and efficient approach to energy harvesting and storage.