Nickel-cobalt-TiO2 co-doped lignin based carbon nanofibers: Versatile integrated material for supercapacitor and microwave absorption

Abstract

The development of multifunctional composites is a challenging but necessary path for the miniaturization and integration of electronic products. Herein, versatile bimetal hydroxide (NiCo2(OH)6) nanowires coated on TiO2 modified lignin based carbon nanofibers (CNFs/TiO2@NiCo2(OH)6) have been prepared successfully by the method of electrospinning followed by hydrothermal treatment. The loading of NiCo2(OH)6, the doping of N, and the modification of TiO2 endow the CNFs/TiO2@NiCo2(OH)6 with multifunctional application in energy storage and microwave absorption (MA). The abundant pores and active sites result in an excellent electrochemical performance with a high specific capacitance of 752.47 F g−1 at 1 A g−1. More importantly, the assembled supercapacitor exhibits a maximum energy density of 60.64 Wh kg−1 and a superior stability of 90.2 % even after 4000 cycles at the current density of 10 A g−1. Moreover, considering the unique porous layered-structure as well as eminent electromagnetic matching properties, as-prepared composites display an excellent MA property, which possesses a minimum reflection loss (RLmin) of −46.48 dB and a maximum effective absorption bandwidth (EAB, RL < 10 dB) of 2 GHz (covering 47.62 % of X-band frequency). This work simultaneously delivers the potential application in the field of energy storage and MA.