Rectification-free flexible piezoelectric supercapacitor with integrated energy harvesting and storage

Self-charging piezoelectric supercapacitors (PSCs) are capable of providing a sustainable power solution for various wearable electronic devices by directly transforming stray mechanical stimuli into electrical energy. Here, we fabricate a flexible, self-charging PSC using MoS2-carbon black (CB) symmetric electrodes, PVA-KOH gel electrolyte, and porous PVDF-BCZT composite film piezo-separator that directly converts and stores mechanical energy into electrochemical energy. We demonstrate charging of the device using finger tapping to an average self-charging voltage of 35 mV in 75 s. The device shows an operating potential window of 0.5 V and a specific capacitance of 84 F g−1 at 10 mV s−1, demonstrating early promise to a sustainable solution of powering the next-generation low-power wearable electronic devices.