An Azo-Based Electrode for All-Around High-Performance Flexible Supercapacitors

Abstract

The photo-rechargeable supercapacitor enables the self-powering of flexible wearable electronics. However, flexible wearable electronics require supercapacitors not only with excellent flexibility but also with high energy density. P-diaminoazobenzene (P-Azo) as a new type of organic electrode material with NN is directly connected to the benzene ring and forms a large π-conjugated system, which makes it have a lower lowest unoccupied molecular orbital (LUMO) energy level, is beneficial to transfer of electrons, and increases the conductivity of organic molecules. In addition, NN can realize the transfer of two electrons, which makes P-Azo have a higher energy density. Asymmetric flexible supercapacitors are fabricated by assembling P-Azo, activated carbon, and an adhesive electrolyte, with 425.2 mW h cm−2 (55.19 Wh kg−1) energy density at a power density of 80 mW cm−2 (10.38 W kg−1), and 90.7% capacitance retention after 80 000 cycles of bending. In this work, supercapacitors and perovskite submodules are coupled to prepare a photo-rechargeable supercapacitor to achieve a 7% overall energy-conversion efficiency. Therefore, this supercapacitor paves a practical route for powering future wearable electronics.