Designing micro-3D hierarchical HZCNF@ZS-LDH@MX as advanced electrodes for flexible supercapacitors

The design of electrode materials is the core for enhancing the practicality of supercapacitors. Herein, we report an electrode material with a micro-3D structure, in which the template-shaped ZnS nanorods are fixed on the hollow carbon nanofibers. Subsequently, ZnCo-LDH nanosheets grow on the surface of ZnS nanorods directionally and form a 3D structure. Finally, an MXene layer is coated on the material surface by electrostatic spraying. Experimental analysis shows that due to the construction of a stable polymetallic compound array and a conductive network, the HZCNF@ZS-LDH@MX electrode can maintain rapid charge transfer, thereby significantly improving the kinetics of ion/electron reactions. Taking these advantage, HZCNF@ZS-LDH@MX has a high specific capacitance of 830 F g⁻¹, a specific surface area of 740 m² g⁻¹, and good cycling stability over 20,000 cycles. In addition, the assembled flexible device reaches an energy density of 65.1 Wh kg⁻¹, which is sufficient to power an LED board. This study proposes an effective strategy for enhancing the ion and charge transport within the hierarchical structure. By making full use of the advantages of two-dimensional materials and designing micro-3D structures, it has opened up new approaches for the development and utilization of supercapacitor electrodes. In addition, according to the special nature of the material, the ability of electromagnetic wave absorbing is further tested. The results showed that the maximum reflection loss is −60 dB, and there is a potential application possibility of dual functions of energy storage and wave absorption.