High-Performance Piezocomposite Energy Harvesters by Constructing Bionic Ion Channels

In recent years, the traditional piezoelectric energy collector lacks effective progress in the field of wearable energy, because the mechanical energy of human body cannot meet its working frequency. In addition, traditional piezoelectric materials cannot obtain sufficient short-circuit current and power density to supply power due to the high impedance of its dielectric layer. Here, in order to solve the carrier shortage in traditional piezoelectric materials, ions are implanted in the piezo-layer and bionic ion channels are constructed to promote ion transport. The piezocomposite energy harvesters achieve a short-circuit current of 13.3 µA at low-frequency pressure, which is two orders of magnitude higher than that of traditional piezoelectric generator. Besides, the double layer structure formed by ions and composite carbon electrode has natural energy storage characteristics. The open-circuit voltage of piezocomposite energy harvesters will gradually accumulate step by step under ultra-low-frequency pressure. The piezocomposite devices can rapidly charge under a low-frequency pressure (20 N, 1 Hz) to obtain an open-circuit voltage of 150 mV within 80 s. This mode of introducing carriers into the piezo-layer to improve the performance of the piezoelectric generator could provide a promising strategy for piezoelectric materials to collect and store low-frequency human mechanical energy.