Nickel bismuth oxide as negative electrode for battery-type asymmetric supercapacitor

One of the main variables for achieving superior electrochemical efficiency is the development of an innovative and advanced supercapacitor negative electrode. This paper presents and explores the development of novel and advanced nanostructures of nickel bismuth oxide and their electrochemical activity as negative electrodes in the construction of a battery-type asymmetric supercapacitor. It could yield a specific capacity of 443 C g(-1) (at 2 mA cm(-2)) within the potential window of -1.1 to 0 V. In addition, NiO/CeO2 nanocomposites have been prepared to improve long term cyclic stability of NiO electrode materials and used as the counter electrode to nickel bismuth oxide in the assembly of supercapacitor cells. A maximum capacity of 543 C g(-1) (at 2 mA cm(-2)) is estimated for the NiO nanocomposites containing 12 mol% ceria in the potential window of -0.05 to 0.4 V. The fabricated NC12//NBO battery-type asymmetric supercapacitor cell reveals Faradic characteristics and they provide the specific capacity of 374 C g(-1) (2 mA cm(-2)) along with 95.6% capacity retention after 5000 GCD cycles. Moreover, the fabricated cell delivers a specific energy of 78 W h kg(-1) (at 201 W kg(-1)) and retains 41.1% energy even at a high specific power of 3.2 kW kg(-1). The NC12//NBO asymmetric cell was used to power 30 Red LEDs. The outstanding electrochemical behaviour of nickel bismuth oxide electrode suggests it to be a promising negative electrode material in the fabrication of asymmetric supercapacitor.