Copper/nickel-based bimetallic heterostructures anchored nitrogen-doped porous carbon for high-energy lithium and sodium-ion-based supercapatteries

Abstract

This study investigates the synthesis of bimetallic Ni-Cu/NiO-Cu₂O heterostructures featuring amorphous-crystalline interfaces anchored on nitrogen-doped porous carbon (N-PC) derived from porous organic frameworks (POFs) for high-performance supercapattery devices (SDs). In this process, Ni²⁺ and Cu²⁺ ions in controlled ratios are incorporated into the POF through a condensation reaction, followed by carbonization under a nitrogen atmosphere at 1000 °C to form Ni-Cu/NiO-Cu₂O@N-PC composites. The coexistence of metallic and metal oxide phases is confirmed through X-ray-based analyses, while Raman spectroscopy and structural characterization verify the presence of amorphous-crystalline interfaces anchored on N-PC. Among the prepared materials, the Ni-Cu/NiO-Cu₂O@N-PC-3 (with a Ni²⁺: Cu²⁺ weight ratio of 75:25) exhibits superior electrochemical performance, delivering a maximum specific capacitance of 940 F g⁻¹ at 1 A g⁻¹. High-energy Li- and Na-based non-aqueous SDs are developed using LiClO₄, NaClO₄, and LiPF₆ electrolytes to ensure high ionic conductivity and wide potential windows. The assembled SD (Ni-Cu/NiO-Cu₂O@N-PC-3 / 1.0 M LiPF₆ (non-aqueous) / Activated carbon) achieves a remarkable energy density of 177 W h kg⁻¹ and a power density of 2723 W kg⁻¹. Furthermore, the fabricated device effectively powers red and yellow LEDs, confirming its potential for practical energy storage applications.