Metallic Layered Polyester Fabric Enabled Nickel Selenide Nanostructures as Highly Conductive and Binderless Electrode with Superior Energy Storage Performance

Highly flexible and conductive fabric (CF)‐supported cauliflower‐like nickel selenide nanostructures (Ni 3 Se 2 NSs) are facilely synthesized by a single‐step chronoamperometry voltage‐assisted electrochemical deposition (ECD) method and used as a positive electrode in supercapacitors (SCs). The CF substrate composed of multi‐layered metallic films on the surface of polyester fibers enables to provide high electrical conductivity as a working electrode in ECD process. Owing to good electrical conductivity, high porosity and intertwined fibrous framework of CF, cauliflower‐like Ni 3 Se 2 NSs are densely integrated onto the entire surface of CF (Ni 3 Se 2 NSs@CF) substrate with reliable adhesion by applying a chronoamperometry voltage of −1.0 V for 240 s. The electrochemical performance of the synthesized cauliflower‐like Ni 3 Se 2 NSs@CF electrode exhibits a maximum specific capacity ( C SC ) of 119.6 mA h g −1 at a discharge current density of 2 A g −1 in aqueous 1 m KOH electrolyte solution. Remarkably, the specific capacity of the same electrode is greatly enhanced by introducing a small quantity of redox‐additive electrolyte into the aqueous KOH solution, indicating the C SC ≈251.82 mA h g −1 at 2 A g −1 with good capacity retention. Furthermore, the assembled textile‐based asymmetric SCs achieve remarkable electrochemical performance such as higher energy and power densities, which are able to light up different colored light‐emitting diodes.