Facilitating rapid ion transport and boosting redox kinetics in Yb/NiCo-LDH composite for enhanced supercapacitor performance

Abstract

A dual atom regulation strategy coupled with anionic defect engineering is shown to be highly effective for tuning the electronic structure and improving the electrochemical behaviour of layered double hydroxides (LDHs). Herein, we present a precisely engineered ytterbium (Yb)doped NiCo-LDH nanocomposite where Yb incorporation enables remarkable charge storage capabilities, achieving a high specific capacitance of 2130 F g⁻¹ at 1 A g⁻¹. Advanced spectroscopic analysis confirms that the incorporation of Yb dopants induces the formation of oxygen vacancies within the host lattice, that collectively modulate the electronic landscape which facilities rapid charge propagation and enhanced charge storage mechanism. To asses practical utility, an asymmetric supercapacitor (ASC) is constructed using the Yb2 as the positive electrode and activated carbon as the negative electrode. introduction of Yb dopants created additional oxygen vacancies within the LDH lattice, which improved the charge transfer and overall electrochemical performance. The assembled ASC device achieves a high energy density of 78 Wh kg⁻¹ at a power density of 751 W kg⁻¹ and demonstrates remarkable operational stability, retaining 81% of its initial capacitance after 10,000 cycles at 20 A g⁻¹, with a coulombic efficiency of 95%. This work establishes a fundamental design principle for next generation energy storage material through synergistic dopant strategies and defect engineering.