Ultrathin,\nWrinkled, Vertically Aligned Co(OH)₂ Nanosheets/Ag Nanowires\nHybrid Network for Flexible Transparent Supercapacitor with High Performance

Abstract

Developing\nhigh-performance, flexible, transparent supercapacitors for wearable\nelectronics represents an important challenge, as it requires active\nmaterials to be sufficiently transparent without compromising energy\nstorage. Here, we manipulate the morphology of the active materials\nand the junctions on the current collector to achieve optimum electronic/ionic\ntransport kinetics. Two-dimensional Co­(OH)₂ nanosheets\nwith single or two layers were vertically aligned onto a modified\nAg nanowires (AgNWs) network using an electrochemical deposition–UV\nirradiation approach. The metallic AgNWs network endows high transparency\nwhile minimizing the contact resistance with the pseudocapacitive\nCo­(OH)₂ nanosheets. The Co­(OH)₂ nanosheets self-assembled\ninto a three-dimensional array, which is beneficial for the fast ion\nmovements. The rational materials design greatly boosts the electrochemical\nperformance of the hybrid network, including an ultrahigh areal capacitance\nup to 3108 μC cm^–2 (5180 μF cm^–2) coupled with long cycle life (20 000 cycles). As a prototype\ndevice, the symmetric supercapacitor well combines high energy/power\ndensity and excellent mechanical flexibility and long-term performance,\nsuggesting a promising application for the next-generation wearable\nelectronics.