Manganese oxide and nickel oxide thin films on polyester to enable self-charging wearable supercapacitor

In this work, an extremely flexible piezoelectric driven self-charging asymmetric supercapacitor (SCAS) has been reported in which nickel oxide (NiO) thin film acts as the negative electrode, manganese oxide (MnO2) thin film as the positive electrode, and PVA-ZnO-KOH (PZK) film as a separator (as well as a piezoelectric material). The results confirmed that even after 7500 charge-discharge cycles, the asymmetrical supercapacitor (MnO2//NiO) showed 100% capacitive retention. Mechanical deformation caused by the impact of a human thumb was used to illustrate the self-charging capabilities of the SCAS, and it was observed that by repeatedly pressing and releasing, the SCAS can charge up to 380 mV within similar to 35 s. Additionally, the SCAS demonstrates incredible storage capacity by holding a voltage of 310 mV for more than a minute. Moreover, the fabricated SCAS was also subjected to bending as well as twisting followed by wetting, and it retained good performance even after wetting several times with distilled water indicating high durability of the device. All of these tests show that the developed supercapacitor has a high degree of flexibility, robustness, durability and stability, as well as a substantial amount of storage and self-charging potential.

Automated summary

In this work, an extremely flexible piezoelectric driven self-charging asymmetric supercapacitor (SCAS) is reported, showing 100% capacitive retention after 7500 charge-discharge cycles and fast charging within a short period of time. Additionally, it demonstrates incredible storage capacity and durability.