One-step electrodeposition synthesis of high performance carbon nanotubes/graphene-doped Ni(OH)2 thin film electrode for high-performance supercapacitor

In this work, we successfully synthesized Ni(OH)(2) thin film electrode in situ doped with CNTs/rGO by cathodic electrodeposition on titanium mesh. The doping effects of CNTs and/or rGO, and the technical conditions, are investigated. The doping of CNTs/rGO can greatly improve the electrochemical performance by forming the porous structure and the conductive network in the Ni(OH)(2) thin film. The highest capacity, 429.5 mAh/g at a current density of 5 A/g, is achieved for the electrode with 0.24 mg/cm(2) Ni(OH)(2) and codoped with CNTs and rGO, as compared with only 323.9 mAh/g for undoped electrode. Even at 100 A/g, the specific capacity can still remain 347.5 mAh/g (vs. 221.5 mAh/g for the undoped electrode), and after 1000 cycles, the retention rate of the specific capacity is 74.9% as compared with only 42.7% for the undoped electrode. Even with higher loading amounts of 1.92 mg/cm(2) Ni(OH)(2), the specific capacity retention rate of the codoped electrode is still much higher than that of the undoped electrode. The high electrochemical performance can be attributed to the better ion/electron transfer ability of the codoped electrode. In conclusion, by the cathodic electrodeposition and in situ doping of CNTs/rGO, the porous structure and the conductive network in Ni(OH)(2) film can be constructed, which can improve the ion/electron transfer ability, therefore, the high performance film electrode with higher loading amount of Ni(OH)(2) can be prepared. (C) 2019 Elsevier Ltd. All rights reserved.