Construction of a P-rGO/CNTs@PANI ternary composite for supercapacitors with balanced energy–power performance

Abstract

This study presents the design of a multi-component composite, phosphate group-modified reduced graphene oxide/carbon nanotubes@polyaniline (P-rGO/CNTs@PANI), as a supercapacitor (SC) electrode. First, a core–shell structured CNTs@PANI structure was constructed via in situ polymerization of aniline on the surface of CNTs. Subsequently, utilizing phosphoric acid as a multifunctional medium, a one-step hydrothermal method was employed to simultaneously reduce and functionalize GO and form a composite together with CNTs@PANI. The covalent grafting of phosphate groups onto the reduced graphene oxide surface effectively inhibited layer restacking while establishing robust interfacial coupling with the PANI chains, thereby forming a conductive interpenetrating network. When the mass ratio of GO to CNTs@PANI was set as 1 : 3, the composite exhibited a specific capacitance of 389.8 F g⁻¹ at 1 A g⁻¹ and over 90% capacity retention after 10 000 cycles. The symmetric SC assembled with the P-rGO/CNTs@PANI electrodes achieved an energy density of 21.9 Wh kg⁻¹ and a power density of 500.9 W kg⁻¹, and was capable of stably powering electronic devices. This research provides a novel strategy for the design of high-performance SC electrodes.