Synergistic Electronic and Structural Engineering in an Fe-NiCo2O4@NiFeCo-LDH Core–Shell Heterostructure toward High-Performance Supercapacitors

Abstract

Nickel-cobalt spinel oxide (NiCo2O4) has attracted extensive research interest as an electrode material for supercapacitors due to its outstanding electrochemical properties; however, its practical performance is often constrained by low intrinsic electrical conductivity, slow ion transport dynamics, and underutilized active sites. In this paper, we successfully constructed a core–shell heterostructure of Fe-NiCo2O4@NiFeCo-LDH on a flexible carbon fabric. By utilizing multi-scale electronic modulation techniques and the multi-metal synergistic pseudocapacitive effect, charge-transfer kinetics and ion transport were significantly improved. The cathode exhibited an excellent specific capacitance of 2536 F g–1 at 1 A g–1. Even after 5000 cycles at 10 A g–1, the electrode maintained 90.91% of its original capacitance. Additionally, the Fe-NiCo2O4@NiFeCo-LDH//AC asymmetric supercapacitor delivered 70.91 Wh kg–1 at 848.67 W kg–1. This work provides an effective approach to improving the electrochemical performance of NiCo2O4-based materials and offers valuable insights into the rational design of advanced high-performance supercapacitor electrodes.