Layer-by-layer inkjet printing GO film and Ag nanoparticles supported nickel cobalt layered double hydroxide as a flexible and binder-free electrode for supercapacitors

Inkjet printing is an attractive technique in the field of flexible electronics due to the direct writing, digital controls and non-contact operation process. In this work, we successfully printed graphite oxide and Ag nanoparticles on the substrate of flexible carbon cloth to form a flexible, conductive and hydrophilic layer, which could be used as a new substrate with an electron transport layer of large surface area. In addition, Ni-Co LDH nanosheets as the main active materials were synthesized for improving the electrochemical activity via a convenient electrochemical deposition method. The binder-free Ni-Co LDH/Ag/rGO@CC electrode exhibits outstanding electrochemical performance along with a high capacity of 173 mA h g(-1) at 1 A g(-1). Moreover, an asymmetric supercapacitor (ASC) was assembled with Ni-Co LDH/Ag/rGO@CC electrode as the positive electrode materials and activated carbon coated CC as the negative electrode materials, showing a high capacity of 95 mA h g(-1) at 0.6 A g(-1) and maximum energy density of 76 Wh kg(-1) at a power density of 480 W kg(-1). (C) 2019 Elsevier Inc. All rights reserved.