NiCo 2 O 4 @Polyaniline Nanotubes Heterostructure Anchored on Carbon Textiles with Enhanced Electrochemical Performance for Supercapacitor Application

NiCo 2 O 4 is one of the most promising supercapacitor electrode materials. However, its capacitance and cycle stability require further improvement for practical application. Herein, a porous NiCo 2 O 4 nanotube [email protected] (NiCo 2 O 4 @PANI) electrode grown directly on carbon textiles is designed and synthesized through a facile two-step method. Electrochemical tests show that the NiCo 2 O 4 @PANI/carbon textiles composite electrode exhibits a higher specific capacity (720.5 C g –1, 10.38 C cm –3 in terms of volumetric capacity) than an electrode of pure NiCo 2 O 4 at a current density of 1 A g –1 . Additionally, the PANI layer is also beneficial to prevent the deformation of the tubular NiCo 2 O 4 and to keep 99.64% capacity retention after 10 000 cycles. The prominent electrochemical capacitive properties of the NiCo 2 O 4 @PANI electrode are not only attributed to the extra pseudo-capacitance originating from PANI but also the synergistic effects of NiCo 2 O 4 and PANI. Detailed investigation of the electrochemical impedance spectroscopy and UV–vis–NIR spectrophotometry data reveals decreased charge transfer resistance. Further mechanism and dynamics analysis based on cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS) reveals that the composite electrode shows enhanced redox and surface-capacitive behavior because of the coated PANI. This work provides an effective strategy to improve the supercapacitor performance by inducing interactions based on heterostructure, and the prepared NiCo 2 O 4 @PANI composite electrode exhibits potential applications in emerging electrochemical energy storage devices.