High-performance and flexible all-solid-state hybrid supercapacitor constructed by NiCoP/CNT and N-doped carbon coated CNT nanoarrays

The exploration of flexible supercapacitors with high energy density is a matter of considerable interest to meet the demand of wearable electronic devices. In this work, with carbon nanotubes (CNTs) grown on carbon cloth (CC) as flexible substrate, NiCoP nanoflake-surrounded CNT nanoarrays (NiCoP/CNT) and Ndoped carbon coated CNT nanoarrays (CNT@N-C) were synthesized on CC and utilized as cathode and anode materials for constructing flexible all-solid-state hybrid supercapacitor. Both them exhibit excellent electrochemical performance. NiCoP/CNT/CC composites can deliver a specific capacitance of 261.4 mAh g(-1), and CNT@N-C/CC exhibits a high capacitance of 256 F g(-1) at the current density of 0.5 A g(-1). The hybrid supercapacitor built from the two well designed electrodes can provide a specific capacitance of 123.3 mAh g(-1) at current density 1 mA g(-1) within a potential window of 0-1.5 V and retain almost 85% of its initial capacitance after 5000 cycles. Furthermore, the flexible devices show the maximum energy density of 138.7 Wh kg(-1) and a power density of 6.25 kW kg(-1), obviously superior to some recent reported supercapacitor devices, indicating its potential in practical application. (C) 2020 Elsevier Inc. All rights reserved.